Thermal therapy

Infrared Sauna

Infrared Sauna is a thermal therapy practice.

Overview

Infrared Sauna is a thermal-therapy practice studied for possible effects on physical recovery and broader wellbeing, alongside metabolic and chronic-health questions. This breadth reflects research across different outcomes rather than one clearly established purpose. Clinical investigations address several possible applications, but support is not uniform across them, and the overall picture remains unsettled. The findings are best understood as questions being examined, rather than proof that the practice reliably produces particular health benefits across all these areas.

Some research: 19 studies. Last checked Oct 9, 2026.

19
human evidence: 9
eligible: 7
unclassified: 10
animal / null result

Best-evidenced uses

Cardiovascular Health SupportMedium · RCT
Fatigue ReductionMedium · Clinical
Muscle Recovery AccelerationLow · Clinical

4 variations documented

EvidenceModerate

19
Studies

Evidence checked Oct 9, 2026 · newest study 2026

Study designs:Meta-analysis1Systematic review1RCT8Quasi Experimental4Cohort study2Cross Sectional1Pilot study2

B: 1
C: 18

319 community reports across 5 platforms

View sources

Coverage

Effects: 35
Helps with: 10
Side effects: 18
Interactions: 10

How to read the evidence

Evidence tier — overall strength of the evidence for the whole compound

StrongWell established — backed by strong, consistent human research.
ModerateSome genuine support, but mostly from small or lower-quality studies. Promising, not proven.
PreliminaryEarly-stage evidence — a promising hypothesis, not an established effect yet.
LimitedVery limited evidence — treat this as a hypothesis, not proof.
InsufficientNot enough good evidence to draw conclusions yet.

Certainty — how sure we can be that the effect is real

Very highVery sure — strong, consistent evidence
HighFairly sure — consistent evidence from good studies
MediumModerately sure — new studies could change this
LowNot sure — little or mixed evidence
Very lowVery unsure — almost no usable evidence

Source — where the data comes from

Meta-analysisPooled analysis of many trials — the strongest evidence
RCTRandomized controlled trial — a strong human study design
ClinicalA human clinical study
Reference knowledgeFrom general health-science or pharmacology references, not a study of this exact claim
Animal researchStudied in animals, not humans
Community reportsAggregated user reports — anecdotal signal, not evidence
TheoreticalMechanism-based reasoning, not yet tested

Study grade — quality of each underlying study (A best, D weakest)

AHigh-quality — strong, consistent human trials
BGood — solid evidence with some limitations
CModerate — limited, small, or mixed-quality studies
DWeak — preliminary, indirect, or animal-only

Confidence — how strongly the sources back a finding

A 0–100 score from study quality and agreement

Most supplement evidence is graded C–D. Read it as preliminary signal, not proof.

These are research findings, not promises. A practice does not replace medical treatment.

What does research say?

What studies found for each claimed effect, best evidence first.

35 claims:2 some evidence18 not enough evidence7 not tested in people2 personal stories only6 no benefit found

What studies foundSize of effect

Cardiovascular Health SupportSome evidence it helpsSize of effect: Not known
Some human studies found a benefit. More research could change this.
All 4 studies with a clear result found a benefit. Strongest study: a pooled analysis of several trials. A trial found it after a single session.
A 2018 pooled analysis associated FIRS therapy with improved left-ventricular ejection fraction. A 2009 review addressed blood-pressure normalization and congestive heart failure, so the findings concern specific cardiovascular measures and conditions.
Open the Cardiovascular Health Support page
Fatigue ReductionSome evidence it helpsSize of effect: Not known
Some human studies found a benefit. More research could change this.
All 3 studies with a clear result found a benefit. Strongest study: a randomized controlled trial.
A 2025 randomized trial of 30 participants reported a mean difference of −13.57 points on Fatigue 4A. Separately, a 2009 review’s support for FIRS therapy in chronic fatigue syndrome came from a single study.
Open the Fatigue Reduction page
Muscle Recovery AccelerationNot enough evidence
Too few or too small studies to know if it works.
3 of 4 studies found a benefit; 1 found none. Strongest study: a randomized controlled trial.
Open the Muscle Recovery Acceleration page
Sleep Quality ImprovementNot enough evidence
Too few or too small studies to know if it works.
1 of 2 studies found a benefit; 1 found none. Strongest study: a randomized controlled trial.
A 2025 randomized trial involving 30 people with major depressive disorder reported an 8.83-point decrease in the Sleep disturbance 4A score.
Open the Sleep Quality Improvement page
Muscle Soreness Reduction (DOMS)Not enough evidence
Too few or too small studies to know if it works.
2 of 3 studies found a benefit; 1 found none. Strongest study: a randomized controlled trial.
Findings in healthy participants disagree. A 2025 randomized trial involving 40 people observed increased soreness 36 hours after exercise only in the control group, and a 2023 trial involving 16 people found lower soreness scores after infrared sauna than after PAS; however, a 2015 trial involving 10 people found no differences in any variables during recovery between infrared sauna and no sauna bathing.
Open the Muscle Soreness Reduction (DOMS) page
Analgesic EffectNot enough evidence
Too few or too small studies to know if it works.
3 of 5 studies found a benefit; 2 found none. Strongest study: a randomized controlled trial.
A 2009 review of randomized and non-randomized human studies described fair evidence from a single study for infrared sauna therapy in chronic pain. In a 2023 randomized trial involving 16 participants, muscle soreness scores were lower after infrared sauna than after PAS at the postREC- and post14h-measurements.
Open the Analgesic Effect page
Anxiety ReductionNot enough evidence
Too few or too small studies to know if it works.
All 2 studies with a clear result found a benefit. Strongest study: a randomized controlled trial.
A 2025 randomized trial involving 30 people with major depressive disorder reported a 7.24-point decrease in the Anxiety 4A score.
Open the Anxiety Reduction page
Blood Glucose Level SupportNot enough evidence
Too few or too small studies to know if it works.
1 of 2 studies found a benefit; 1 found none. Strongest study: a non-randomized trial.
In a 2025 quasi-experimental study involving 14 people with type 2 diabetes, plasma glucose iAUC was lower over the postprandial period following 8 weeks of PHT.
Open the Blood Glucose Level Support page

Social Function ImprovementNot enough evidence
Too few or too small studies to know if it works.
The one study found a benefit. Strongest study: a randomized controlled trial.
A 2025 randomized trial involving 30 people with major depressive disorder reported a 13.04-point increase in Social role abilities 4A.
Open the Social Function Improvement page
Improve Heart Rate Variability (HRV)Not enough evidence
Too few or too small studies to know if it works.
1 of 2 studies found a benefit; 1 found none. Strongest study: a non-randomized trial.
A 2022 quasi-experimental study involving 16 people concluded that infrared sauna following maximal exercise supported some ANS recovery.
Open the Improve Heart Rate Variability (HRV) page
Blood Flow ImprovementNot enough evidence
Too few or too small studies to know if it works.
All 3 studies with a clear result found a benefit. Strongest study: a randomized controlled trial.
A 2026 randomized trial involving 10 people with chronic kidney disease found FMD was greater following HT than control. A 2013 cross-sectional study described development of an endothelium-independent vasodilation mechanism by the end of the treatment period.
Open the Blood Flow Improvement page
Physical Endurance IncreaseNot enough evidence
Too few or too small studies to know if it works.
The one study found a benefit. Strongest study: a randomized controlled trial.
Open the Physical Endurance Increase page
Antidepressant EffectNot enough evidence
Too few or too small studies to know if it works.
1 of 2 studies found a benefit; 1 found none. Strongest study: a randomized controlled trial.
A 2025 randomized trial involving 30 people with major depressive disorder reported an average 19.07-point decrease in Beck Depression Inventory-II scores in the WBH arm.
Open the Antidepressant Effect page
Physical Energy IncreaseNot enough evidence
Too few or too small studies to know if it works.
The one study found a benefit. Strongest study: a systematic review of studies.
A review of randomized and non-randomized human studies described weak support from a single study for Infrared Sauna therapy in Chronic Fatigue Syndrome.
Open the Physical Energy Increase page
Stress Resilience ImprovementNot enough evidence
Too few or too small studies to know if it works.
The one study found a benefit. Strongest study: a non-randomized trial.
A quasi-experimental study in people with Diabetes Type 2 found that self-reported stress and fatigue improved on Visual Analogue Scales.
Open the Stress Resilience Improvement page
Increased Growth Hormone ReleaseNot enough evidence
Too few or too small studies to know if it works.
The one study found a benefit. Strongest study: a randomized controlled trial.
In a randomized trial of 10 healthy participants, serum growth hormone increased after both Infrared Sauna and traditional sauna, with the highest levels after sauna and at 30 min of recovery.
Open the Increased Growth Hormone Release page
Antioxidant Protection EnhancementNot enough evidence
Too few or too small studies to know if it works.
All 2 studies with a clear result found a benefit. Strongest study: a one-time survey study.
A cross-sectional study reported activation of antioxidant protection by the end of the treatment period.
Open the Antioxidant Protection Enhancement page
Mood ImprovementNot enough evidence
Too few or too small studies to know if it works.
The one study found a benefit. Strongest study: a small pilot study.
Open the Mood Improvement page
Weight Management SupportNot enough evidence
Too few or too small studies to know if it works.
The one study found a benefit. Strongest study: a systematic review of studies.
A 2009 review described support for FIRS therapy in people with obesity, but noted that it came from a single study.
Open the Weight Management Support page
Blood Pressure SupportNot enough evidence
Too few or too small studies to know if it works.
3 of 4 studies found a benefit; 1 found none. Strongest study: a randomized controlled trial.
Open the Blood Pressure Support page
Parasympathetic ActivationNot tested in people
Only tested in animals, cells or theory. Results like these often do not carry over to people.
The one study found a benefit.
A proposed explanation is that Infrared Sauna may promote vagal tone and shift autonomic balance toward parasympathetic dominance, measurable through increased HRV and a reduced LF/HF ratio.
Open the Parasympathetic Activation page
Nitric Oxide Production IncreaseNot tested in people
Only tested in animals, cells or theory. Results like these often do not carry over to people.
The one study found a benefit.
A proposed mechanism is that heat exposure stimulates endothelial nitric oxide synthase (eNOS), increasing NO bioavailability and contributing to vasodilation and blood pressure reduction.
Open the Nitric Oxide Production Increase page
Longevity and Anti-Aging SupportNot tested in people
Only tested in animals, cells or theory. Results like these often do not carry over to people.
The one study found a benefit.
Frequent sauna use has been associated with reduced risk of all-cause mortality and cardiovascular death, independent of other lifestyle factors.
Open the Longevity and Anti-Aging Support page
Immune System SupportNot tested in people
Only tested in animals, cells or theory. Results like these often do not carry over to people.
1 of 2 studies found a benefit; 1 found none.
Immune system support remains theoretical; human evidence has not established this effect.
Open the Immune System Support page
Inflammation ReductionNot tested in people
Only tested in animals, cells or theory. Results like these often do not carry over to people.
1 of 2 studies found a benefit; 1 found none.
Inflammation reduction remains theoretical; human evidence has not established this effect.
Open the Inflammation Reduction page
Insulin Sensitivity ImprovementNot tested in people
Only tested in animals, cells or theory. Results like these often do not carry over to people.
1 of 2 studies found a benefit; 1 found none.
An improvement in insulin sensitivity remains theoretical; human evidence has not established this effect in people with type 2 diabetes.
Open the Insulin Sensitivity Improvement page
Mitochondrial Function SupportNot tested in people
Only tested in animals, cells or theory. Results like these often do not carry over to people.
1 of 2 studies found a benefit; 1 found none.
Studies did not support improved mitochondrial function: a 2025 quasi-experimental study involving 14 people observed no changes in muscle mitochondrial content and function after the PHT intervention.
Open the Mitochondrial Function Support page
Skin Health ImprovementOnly personal stories
Only people's own stories online. No study has tested it.
The one study found a benefit.
Sweating may open pores, while increased blood flow in the skin may support skin cleansing and nutrient delivery. This effect was mentioned in 8 of 233 community reports.
Open the Skin Health Improvement page
Heat ToleranceOnly personal stories
Only people's own stories online. No study has tested it.
The one study found a benefit.
Repeated controlled heat exposure can produce heat acclimation and improve tolerance of later heat exposure; how much Infrared Sauna does so depends on the heat dose. This effect was mentioned in 2 of 233 community reports.
Open the Heat Tolerance page
Physical Strength IncreaseNo benefit found
Studies looked for a benefit and did not find one.
0 of 3 studies found a benefit; 3 found none. Strongest study: a randomized controlled trial.
Open the Physical Strength Increase page
Muscle Mass IncreaseNo benefit found
Studies looked for a benefit and did not find one.
0 of 2 studies found a benefit; 2 found none. Strongest study: a non-randomized trial.
Studies did not support an increase in muscle mass: a 2025 quasi-experimental study involving 14 people found no change in vastus lateralis muscle CSA.
Open the Muscle Mass Increase page
Kidney Health SupportNo benefit found
Studies looked for a benefit and did not find one.
The one study found no benefit. Strongest study: a randomized controlled trial.
The studies did not support improved kidney health. A randomized trial of 10 people with Chronic Kidney Disease found no effect on kidney function or markers of kidney injury.
Open the Kidney Health Support page
Cholesterol Level ReductionNo benefit found
Studies looked for a benefit and did not find one.
The one study found no benefit. Strongest study: a systematic review of studies.
Studies did not support cholesterol reduction: a 2009 review of randomized and non-randomized human studies reported consistent fair evidence against claims that infrared sauna reduces cholesterol.
Open the Cholesterol Level Reduction page
Physical FunctionNo benefit found
Studies looked for a benefit and did not find one.
The one study found no benefit.
Studies did not support improved physical function in people with major depressive disorder: a 2025 randomized trial involving 30 people reported a 3.55-point increase in Physical function 4A, with an interval of.
Open the Physical Function page
Detoxification SupportNo benefit found
Studies looked for a benefit and did not find one.
The one study found no benefit.
Studies did not support detoxification: a 2020 cohort study involving 255 people reported a non-significant reduction in total mean PAH-OHs of −43.5%.
Open the Detoxification Support page

Show all 35

Only reported by users, not studied: Chronic Pain Reduction, Cellular Energy Support, Biorhythm Regulation, and Sleep Onset Improvement.

What to expect

Infrared Sauna has been studied both as a single-session experience and in repeated programmes. Some possible effects were observed after one session, while reported side effects occurred either immediately or during programmes lasting several weeks. These study findings do not establish a predictable timeline for an individual, and an immediate change should not be assumed.

Also studied in people with 10 health conditions

How strong the evidence is in each group. This is research, not a treatment recommendation.

What studies foundSize of effect

Chronic Fatigue SyndromeNot enough evidence
Too few or too small studies to know if it works.
All 2 studies with a clear result found a benefit.
The cited review drew on randomized and non-randomized human studies; the finding does not describe a specific change in chronic fatigue syndrome symptoms.
Open the Chronic Fatigue Syndrome page
Chronic PainNot enough evidence
Too few or too small studies to know if it works.
All 2 studies with a clear result found a benefit.
A 2009 review drawing on randomized and non-randomized human studies considered people with chronic pain alongside groups with coronary artery disease, heart failure, and obesity.
Open the Chronic Pain page
Diabetes Type 2Not enough evidence
Too few or too small studies to know if it works.
1 of 2 studies found a benefit; 1 found none.
A 2010 quasi-experimental study of people with type 2 diabetes reported quality-of-life outcomes.
Open the Diabetes Type 2 page
Hypertension (High Blood Pressure)Not enough evidence
Too few or too small studies to know if it works.
All 2 studies with a clear result found a benefit.
A 2009 systematic review of randomized and non-randomized human studies reported possible blood-pressure normalization in populations that included people with chronic pain, coronary artery disease, heart failure, and obesity.
Open the Hypertension (High Blood Pressure) page
Ankylosing SpondylitisNot enough evidence
Too few or too small studies to know if it works.
The one study found a benefit.
A 2009 single-arm pilot study reported good tolerance and short-term improvements in pain and stiffness among 17 people with ankylosing spondylitis.
Open the Ankylosing Spondylitis page
Chronic Kidney DiseaseNot enough evidence
Too few or too small studies to know if it works.
The one study found a benefit.
A 2026 randomized trial tested acute passive heat exposure in 10 people with chronic kidney disease; the findings were described as informing future trials of chronic heat therapy for cardiovascular health.
Open the Chronic Kidney Disease page
DepressionNot enough evidence
Too few or too small studies to know if it works.
The one study found a benefit.
A 2025 trial of 30 people with depression found reductions in BDI-II and high remission rates in both the WBH and sham-WBH groups. It was not designed to reliably compare the groups and did not include a CBT-only control.
Open the Depression page
ObesityNot enough evidence
Too few or too small studies to know if it works.
The one study found a benefit.
A 2009 review considered obesity alongside chronic pain, coronary artery disease, and heart failure, drawing on randomized and non-randomized human studies.
Open the Obesity page

Show all 10

Before you try it

What studies and reports say about side effects and who it may not suit.

Side effects

Possible: Heart Rate Increase and Fluid Loss (Diuretic Effect).

16 more with weak evidence.

May not suit you if you have

Acute Febrile Illness, Heart Arrhythmia, Orthostatic Hypotension, Pregnancy, Recent Heart Attack (MI), Acute Kidney Injury, and 4 more

Reported by users

Physical Fatigue (6 posts), Paresthesia (Tingling/Numbness), and Skin Rash / Irritation

General wellness information, not medical advice. Ask a doctor before you start, especially if you take medicines or have a health condition.

How people do it

A gentle start, then what the studies used.

Start with: 10 minutes (Gentle Evening Relaxation)A gentle start based on the easiest variation, not on a study.
Build up to: 28 minutes, 3 times a week, low intensity (what the studies used)
What the studies ran: 6 weeks
Temperature: about 49–60 °C

The expert view shows every study, dose protocol and source.

Effects

What it changes in the body35 listed

Start here

Most likely to help, from the evidence we have

Cardiovascular Health SupportCertaintyMediumSourceRCT3 cited studies · 2 other sources
A 2018 pooled analysis associated FIRS therapy with improved left-ventricular ejection fraction. A 2009 review addressed blood-pressure normalization and congestive heart failure, so the findings concern specific cardiovascular measures and conditions.
What the sources found
5 positive · 0 neutral · 0 negativeconfidence 40/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people and patients
Chronic Kidney Disease
Chronic Pain
Coronary Artery Disease
Heart Failure (CHF)
Obesity
Where the evidence comes from
Article3
Expert opinion1
Community reports1
What worked in trials2 trials and meta-analyses
Randomized trials and meta-analyses that found this benefit: the smallest and the typical amount. Not a target and not a limit.
Smallest Typical
Session 15 min 20 min
Derived from (2)
30239008 42113470
Timing
A trial found it after a single session
Show studies (5)
Meta-analysisBpositive40% confidence2018
Effects of sauna bath on heart failure: A systematic review and meta-analysis.
was associated with ... an improvement in left-ventricular ejection fraction
Inactive control
PMID 30239008
Systematic reviewCpositive30% confidence2009
Far-infrared saunas for treatment of cardiovascular risk factors: summary of published evidence.
There is limited moderate evidence supporting FIRS efficacy in normalizing blood pressure and treating congestive heart failure
Studies disagree
PMID 19602651
RCTCpositiven=1045% confidence2026
Acute effects of passive heat exposure on vascular function and exercise capacity in patients with chronic kidney disease.
FMD (3.84 ± 0.61 vs. 6.68 ± 0.76%, P P = 0.01) were greater following HT compared with CON.
MD 2.84Top journalMain outcomeOpen-labelSham comparison
PMID 42113470
Expert opinionpositive50% confidence
Regular sauna use is associated with reduced cardiovascular mortality, improved endothelial function, and lower blood pressure.
Expert knowledge synthesis
Community reportsmoderate effectpositive35% confidence
This effect was mentioned in 4 of 233 Reddit reports discussing it.
4 mentions
Open Cardiovascular Health Support
→
Fatigue ReductionCertaintyMediumSourceClinical3 cited studies · 1 other source
A 2025 randomized trial of 30 participants reported a mean difference of −13.57 points on Fatigue 4A (−18.63 to −8.51). Separately, a 2009 review’s support for FIRS therapy in chronic fatigue syndrome came from a single study.
What the sources found
4 positive · 0 neutral · 0 negativeconfidence 33/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people and patients
Chronic Pain
Coronary Artery Disease
Diabetes Type 2
Heart Failure (CHF)
Major Depressive Disorder
Obesity
Where the evidence comes from
Article3
Community reports1
Protocol behind this outcome
2 protocolsEstimated
What the studies reporting this result did.
64 min
Course
11 weeks
Intensity
Low
Format
Individual
Supervision
Instructor-led
Courses and single sessions · 1 repeated-course and 1 single-session protocols
Show studies (4)
Systematic reviewCpositive15% confidence2009
Far-infrared saunas for treatment of cardiovascular risk factors: summary of published evidence.
weak evidence, from a single study, supporting FIRS therapy in chronic fatigue syndrome
PMID 19602651
RCTCpositiven=3060% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Fatigue 4A: −13.57 (2.58)***
MD -13.57 [-18.63, -8.51]Sham-controlledSham comparisonCompleters only
PMID 41146956
Quasi ExperimentalCpositive30% confidence2010
The effects of repeated thermal therapy on quality of life in patients with type II diabetes mellitus.
Visual Analogue Scales for stress and fatigue improved.
Low-quality journalOpen-labelNo control group
PMID 20569036
Community reportssubtle effectpositive25% confidence
This effect was mentioned in 2 of 233 Reddit reports discussing it.
2 mentions
Open Fatigue Reduction
→

	Smallest	Typical
Session	15 min	20 min

Low probability(27)

Muscle Recovery AccelerationCertaintyLowSourceClinical3 cited studies · 2 other sources
In a 2023 randomized trial involving 16 healthy participants, infrared sauna attenuated the relative drop in CMJ performance from before to 14 hours after exercise compared with PAS. A 2015 randomized trial involving 10 people also found higher CMJ at 30 min after infrared sauna bathing than after sitting without sauna: 0.34 ± 0.09 m versus 0.32 ± 0.0 m.
What the sources found
4 positive · 1 neutral · 0 negativeconfidence 52/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Rating adjusted
Lowered from Medium to Low after checking study quality: journal, risk of bias, trial size and design.
Who was studied
Healthy people
Where the evidence comes from
Article3
Expert opinion1
Community reports1
Protocol behind this outcome
1 protocolMeasured
What the studies reporting this result did.
Format
Individual
Supervision
Instructor-led
Single sessions · 0 repeated-course and 1 single-session protocols
What worked in trials2 trials and meta-analyses
Randomized trials and meta-analyses that found this benefit: the smallest and the typical amount. Not a target and not a limit.
Smallest Typical
Session 20 min 25 min
Derived from (2)
26180741 37398966
Timing
A trial found it after a single session
Show studies (5)
RCTCneutraln=4045% confidence2025
Salivary cortisol response to post-exercise infrared sauna declines over time.
we observed that, overall, perceived recovery was higher in the IRS group.
Top journalOpen-labelCompleters only
PMID 40926789
RCTCpositiven=1670% confidence2023
A post-exercise infrared sauna session improves recovery of neuromuscular performance and muscle soreness after resistance exercise training.
IRS attenuated the relative reduction in CMJ performance from pre- to post14h (p = 0.009, ES = 0.76) compared to PAS.
-3.9%Trivial effectTop journalMain outcomeOpen-labelCompleters only31% dropped out
PMID 37398966
RCTCpositiven=1045% confidence2015
Effects of far-infrared sauna bathing on recovery from strength and endurance training sessions in men.
During recovery at 30 min, CMJ was significantly (p < 0.05) higher (0.34 ± 0.09 m) after FIRS bathing than after sitting with NO SAUNA (0.32 ± 0.0 m).
MD 0.02Low-quality journalOpen-labelNo control groupBorderline p-value
PMID 26180741
Expert opinionpositive50% confidence
Infrared sauna enhances post-exercise recovery by reducing delayed onset muscle soreness and accelerating clearance of lactate and inflammatory markers, especially when used after resistance or endurance training.
Expert knowledge synthesis
Community reportsmoderate effectpositive50% confidence
This effect was mentioned in 15 of 248 community reports discussing it (Reddit 13, Bluesky 2).
15 mentions
Open Muscle Recovery Acceleration
→
Sleep Quality ImprovementCertaintyLowSourceClinical2 cited studies · 1 other source
A 2025 randomized trial involving 30 people with major depressive disorder reported an 8.83-point decrease in the Sleep disturbance 4A score.
What the sources found
2 positive · 1 neutral · 0 negativeconfidence 60/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people and patients
Major Depressive Disorder
Where the evidence comes from
Article2
Community reports1
Protocol behind this outcome
1 protocolEstimated
What the studies reporting this result did.
99 min
Course
11 weeks
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (3)
RCTCpositiven=3060% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Sleep disturbance 4A: −8.83 (2.26)**
MD -8.83 [-13.25, -4.4]Sham-controlledSham comparisonCompleters onlyBorderline p-value
PMID 41146956
RCTCneutraln=1670% confidence2023
A post-exercise infrared sauna session improves recovery of neuromuscular performance and muscle soreness after resistance exercise training.
Sleep duration and quality did not differ between IRS and PAS (duration: p = 0.377; quality: p = 0.632).
Top journalOpen-labelCompleters only31% dropped out
PMID 37398966
Community reportsmoderate effectpositive50% confidence
This effect was mentioned in 30 of 269 community reports discussing it (Reddit 27, YouTube 3).
30 mentions
Open Sleep Quality Improvement
→
Muscle Soreness Reduction (DOMS)CertaintyLowSourceClinical3 cited studies · 1 other source
Findings in healthy participants disagree. A 2025 randomized trial involving 40 people observed increased soreness 36 hours after exercise only in the control group, and a 2023 trial involving 16 people found lower soreness scores after infrared sauna than after PAS; however, a 2015 trial involving 10 people found no differences in any variables during recovery between infrared sauna and no sauna bathing.
What the sources found
3 positive · 1 neutral · 0 negativeconfidence 53/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Rating adjusted
Lowered from Medium to Low after checking study quality: journal, risk of bias, trial size and design.
Who was studied
Healthy people
Where the evidence comes from
Article3
Community reports1
What worked in trials2 trials and meta-analyses
Randomized trials and meta-analyses that found this benefit: the smallest and the typical amount. Not a target and not a limit.
Smallest Typical
Session 10 min 15 min
Derived from (2)
37398966 40926789
Timing
A trial found it after a single session
Show studies (4)
RCTCpositiven=4050% confidence2025
Salivary cortisol response to post-exercise infrared sauna declines over time.
Increased muscle soreness was observed at EX1 post36h only in the CON-group.
Top journalOpen-labelCompleters only
PMID 40926789
RCTCpositiven=1670% confidence2023
A post-exercise infrared sauna session improves recovery of neuromuscular performance and muscle soreness after resistance exercise training.
Absolute muscle soreness scores were lower after IRS compared to PAS at the postREC- (p = 0.003, ES = 0.53) and post14h-measurements (p = 0.005, ES = 0.50).
MD -2.3Top journalOpen-labelCompleters only31% dropped out
PMID 37398966
RCTCneutraln=1040% confidence2015
Effects of far-infrared sauna bathing on recovery from strength and endurance training sessions in men.
During recovery there were no differences in any variables between FIRS and no sauna bathing (NO SAUNA).
Low-quality journalOpen-labelNo control group
PMID 26180741
Community reportsmoderate effectpositive50% confidence
This effect was mentioned in 8 of 233 Reddit reports discussing it.
8 mentions
Open Muscle Soreness Reduction (DOMS)
→
Analgesic EffectCertaintyLowSourceClinical4 cited studies · 2 other sources
A 2009 review of randomized and non-randomized human studies described fair evidence from a single study for infrared sauna therapy in chronic pain. In a 2023 randomized trial involving 16 participants, muscle soreness scores were lower after infrared sauna than after PAS at the postREC- and post14h-measurements.
What the sources found
4 positive · 2 neutral · 0 negativeconfidence 43/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people and patients
Ankylosing Spondylitis
Chronic Pain
Coronary Artery Disease
Heart Failure (CHF)
Major Depressive Disorder
Obesity
+1 more
Where the evidence comes from
Article4
Expert opinion1
Community reports1
Protocol behind this outcome
1 protocolMeasured
What the studies reporting this result did.
20 min
Format
Individual
Supervision
Instructor-led
Single sessions · 0 repeated-course and 1 single-session protocols
Timing
A trial found it after a single session
Show studies (6)
Systematic reviewCpositive20% confidence2009
Far-infrared saunas for treatment of cardiovascular risk factors: summary of published evidence.
fair evidence, from a single study, supporting FIRS therapy in chronic pain
PMID 19602651
RCTCneutraln=3060% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Pain interference 4A: −0.39 (2.09) (–4.48, 3.71)
MD -0.39 [-4.48, 3.71]Sham-controlledSham comparisonCompleters only
PMID 41146956
RCTCpositiven=1670% confidence2023
A post-exercise infrared sauna session improves recovery of neuromuscular performance and muscle soreness after resistance exercise training.
Absolute muscle soreness scores were lower after IRS compared to PAS at the postREC- (p = 0.003, ES = 0.53) and post14h-measurements (p = 0.005, ES = 0.50).
MD -2.3Top journalOpen-labelCompleters only31% dropped out
PMID 37398966
Pilot studyCneutraln=3430% confidence2009
Infrared sauna in patients with rheumatoid arthritis and ankylosing spondylitis. A pilot study showing good tolerance, short-term improvement of pain and stiffness, and a trend towards long-term beneficial effects.
In the RA and AS patients, pain, stiffness, and fatigue also showed clinical improvements during the 4-week treatment period, but these did not reach statistical significance.
Open-labelNo control group
PMID 18685882
Expert opinionpositive50% confidence
Heat therapy is a non-pharmacological analgesic, reducing pain through increased blood flow and muscle relaxation.
Expert knowledge synthesis
Community reportsmoderate effectpositive25% confidence
This effect was mentioned in 2 of 233 Reddit reports discussing it.
2 mentions
Open Analgesic Effect
→
Anxiety ReductionCertaintyLowSourceClinical1 cited study · 2 other sources
A 2025 randomized trial involving 30 people with major depressive disorder reported a 7.24-point decrease in the Anxiety 4A score.
What the sources found
3 positive · 0 neutral · 0 negativeconfidence 52/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Major Depressive Disorder
Where the evidence comes from
Article1
Expert opinion1
Community reports1
Protocol behind this outcome
1 protocolEstimated
What the studies reporting this result did.
99 min
Course
11 weeks
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (3)
RCTCpositiven=3060% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Anxiety 4A: −7.24 (1.63)***
MD -7.24 [-10.44, -4.04]Sham-controlledSham comparisonCompleters only
PMID 41146956
Expert opinionpositive50% confidence
Infrared sauna induces parasympathetic activation and reduces cortisol, leading to reductions in perceived anxiety.
Expert knowledge synthesis
Community reportsmoderate effectpositive45% confidence
This effect was mentioned in 6 of 233 Reddit reports discussing it.
6 mentions
Open Anxiety Reduction
→
Blood Glucose Level SupportCertaintyLowSourceClinical2 cited studies
In a 2025 quasi-experimental study involving 14 people with type 2 diabetes, plasma glucose iAUC was lower over the postprandial period following 8 weeks of PHT.
What the sources found
1 positive · 1 neutral · 0 negativeconfidence 58/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people and patients
Diabetes Type 2
Where the evidence comes from
Article2
Protocol behind this outcome
1 protocolMeasured
What the studies reporting this result did.
45 min · 3×/week
Course
8 weeks
Per week
135 min
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (2)
RCTCneutraln=1260% confidence2024
A Single Sauna Session Does Not Improve Postprandial Blood Glucose Handling in Individuals with Type 2 Diabetes Mellitus: A Cross-Over, Randomized, Controlled Trial.
No differences were observed in plasma insulin concentrations (heated: 380±194 vs. thermoneutral: 376±210 pmol/L/120 min; P=0.93).
MD 4Open-labelCompleters only
PMID 39209309
Quasi ExperimentalCpositiven=1455% confidence2025
Repeated passive heat treatment increases muscle tissue capillarization, but does not affect postprandial muscle protein synthesis rates in healthy older adults.
Plasma glucose iAUC was significantly lower over the postprandial period following 8 weeks of PHT (P = 0.024)
Top journalOpen-labelNo control groupCompleters only99% dropped out
PMID 39373667
Open Blood Glucose Level Support
→
Social Function ImprovementCertaintyLowSourceClinical1 cited study
A 2025 randomized trial involving 30 people with major depressive disorder reported a 13.04-point increase in Social role abilities 4A.
What the sources found
1 positive · 0 neutral · 0 negativeconfidence 60/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Major Depressive Disorder
Where the evidence comes from
Article1
Protocol behind this outcome
1 protocolEstimated
What the studies reporting this result did.
99 min
Course
11 weeks
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (1)
RCTCpositiven=3060% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Social role abilities 4A: 13.04 (2.36)***
MD 13.04 [8.41, 17.67]Sham-controlledSham comparisonCompleters only
PMID 41146956
Open Social Function Improvement
→
Improve Heart Rate Variability (HRV)CertaintyLowSourceClinical2 cited studies
A 2022 quasi-experimental study involving 16 people concluded that infrared sauna following maximal exercise supported some ANS recovery.
What the sources found
1 positive · 1 neutral · 0 negativeconfidence 53/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people and patients
Where the evidence comes from
Article2
Show studies (2)
RCTCneutraln=1670% confidence2023
A post-exercise infrared sauna session improves recovery of neuromuscular performance and muscle soreness after resistance exercise training.
No differences in the changes from night before to night after values were observed between the recovery protocols. There was no significant time or treatment effect on nocturnal HR and HRV.
Top journalOpen-labelCompleters only31% dropped out
PMID 37398966
Quasi ExperimentalCpositiven=1635% confidence2022
Autonomic Nervous System Response to Far-Infrared Sauna Exposure in Firefighters.
Conclusions: These findings indicate that FIRS following maximal exercise did support some ANS recovery...
Main outcomeNo control group
PMID 34632485
Open Improve Heart Rate Variability (HRV)
→
Blood Flow ImprovementCertaintyLowSourceClinical2 cited studies · 2 other sources
A 2026 randomized trial involving 10 people with chronic kidney disease found FMD was greater following HT than control (3.84 ± 0.61 vs. 6.68 ± 0.76%, P P = 0.01). A 2013 cross-sectional study described development of an endothelium-independent vasodilation mechanism by the end of the treatment period.
What the sources found
4 positive · 0 neutral · 0 negativeconfidence 38/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Chronic Kidney Disease
Where the evidence comes from
Article2
Expert opinion1
Community reports1
Timing
A trial found it after a single session
Show studies (4)
RCTCpositiven=1045% confidence2026
Acute effects of passive heat exposure on vascular function and exercise capacity in patients with chronic kidney disease.
FMD (3.84 ± 0.61 vs. 6.68 ± 0.76%, P P = 0.01) were greater following HT compared with CON.
MD 2.84Top journalMain outcomeOpen-labelSham comparison
PMID 42113470
Cross SectionalCpositive20% confidence2013
[The influence of general infrared sauna on the antioxidant systems in the blood of volunteers].
The molecular mechanism of endothelium-independent vasodilation develops by the end of the treatment period
Open-labelNo control group
PMID 24437201
Expert opinionpositive50% confidence
Infrared heat causes peripheral vasodilation, increasing blood flow to skin and muscles, which aids nutrient delivery and waste removal.
Expert knowledge synthesis
Community reportsmoderate effectpositive36% confidence
This effect was mentioned in 5 of 269 community reports discussing it (Reddit 3, YouTube 2).
5 mentions
Open Blood Flow Improvement
→
Physical Endurance IncreaseCertaintyLowSourceClinical1 cited study · 1 other source
A randomized trial in 10 people with Chronic Kidney Disease reported a 38 yards difference in 6-min walk distance between the comparison condition (632 ± 29 yards) and HT (670 ± 30 yards).
What the sources found
2 positive · 0 neutral · 0 negativeconfidence 45/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Chronic Kidney Disease
Where the evidence comes from
Article1
Community reports1
Timing
A trial found it after a single session
Show studies (2)
RCTCpositiven=1040% confidence2026
Acute effects of passive heat exposure on vascular function and exercise capacity in patients with chronic kidney disease.
There was a clinically meaningful difference in 6-min walk distance between CON (632 ± 29 yards) and HT (670 ± 30 yards, P
MD 38Top journalOpen-labelSham comparison
PMID 42113470
Community reportsmoderate effectpositive50% confidence
This effect was mentioned in 10 of 233 Reddit reports discussing it.
10 mentions
Open Physical Endurance Increase
→
Antidepressant EffectCertaintyLowSourceClinical2 cited studies
A 2025 randomized trial involving 30 people with major depressive disorder reported an average 19.07-point decrease in Beck Depression Inventory-II scores in the WBH arm.
What the sources found
1 positive · 1 neutral · 0 negativeconfidence 38/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people and patients
Major Depressive Disorder
Where the evidence comes from
Article2
Protocol behind this outcome
1 protocolEstimated
What the studies reporting this result did.
99 min
Course
11 weeks
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (2)
RCTCpositiven=3060% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
The average decreases in the Beck Depression Inventory-II (BDI-II) were −19.07 (SE = 2.69, P < 0.0001) in the WBH arm
MD -19.07 [-24.34, -13.79]Sham-controlledSham comparisonCompleters only
PMID 41146956
Pilot studyCneutraln=2515% confidence2021
Feasibility and acceptability of a Whole-Body hyperthermia (WBH) protocol.
participants evidenced reductions (t [24] = 2.03, M diff = 1.00, p =.054, 95% CI [-2.02,0.02]) in self-reported depression symptoms from 1 week pre- to 1 week post-WBH
MD -1 [-2.02, 0.02]Open-labelNo control group
PMID 34674592
Open Antidepressant Effect
→
Physical Energy IncreaseCertaintyLowSourceClinical1 cited study · 1 other source
A review of randomized and non-randomized human studies described weak support from a single study for Infrared Sauna therapy in Chronic Fatigue Syndrome.
What the sources found
2 positive · 0 neutral · 0 negativeconfidence 33/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people and patients
Coronary Artery Disease
Heart Failure (CHF)
Obesity
Where the evidence comes from
Article1
Community reports1
Show studies (2)
Systematic reviewCpositive15% confidence2009
Far-infrared saunas for treatment of cardiovascular risk factors: summary of published evidence.
weak evidence, from a single study, supporting FIRS therapy in chronic fatigue syndrome
PMID 19602651
Community reportsmoderate effectpositive50% confidence
This effect was mentioned in 12 of 233 Reddit reports discussing it.
12 mentions
Open Physical Energy Increase
→
Blood Pressure SupportCertaintyLowSourceClinicalconflicting findingsnot used for recommendations3 cited studies · 2 other sources
A randomized trial of 12 participants found diastolic blood pressure fell from 78±6 to 63±11 mmHg immediately after heat exposure, then measured 72±11 mmHg at t=120; a quasi-experimental study in 14 people with Diabetes Type 2 reported a 2% reduction in average systolic blood pressure following 8 weeks of PHT. Findings conflict with a pooled analysis of randomized and non-randomized human studies, which found no significant effect on systolic or diastolic blood pressure.
What the sources found
4 positive · 1 neutral · 0 negativeconfidence 42/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people and patients
Diabetes Type 2
Heart Failure (CHF)
Where the evidence comes from
Article3
Expert opinion1
Community reports1
Protocol behind this outcome
2 protocolsMeasured
What the studies reporting this result did.
43 min · 3×/week
Course
8 weeks
Per week
135 min
Intensity
High
Format
Individual
Supervision
Instructor-led
Courses and single sessions · 1 repeated-course and 1 single-session protocols
Timing
A trial found it after a single session
Why it isn't used for recommendations
Best neutral/negative study outranks the best positive study
Show studies (5)
Meta-analysisBneutral20% confidence2018
Effects of sauna bath on heart failure: A systematic review and meta-analysis.
There was no significant effect on ... systolic blood pressure, or diastolic blood pressure
Inactive control
PMID 30239008
RCTCpositiven=1260% confidence2024
A Single Sauna Session Does Not Improve Postprandial Blood Glucose Handling in Individuals with Type 2 Diabetes Mellitus: A Cross-Over, Randomized, Controlled Trial.
During HOT, DBP decreased from 78±6 to 63±11 mmHg between baseline and t=0 (P<0.001) and did not return to baseline at t=120 (72±11 mmHg; P=0.011), while no changes over time occurred during CON. DBP was lower in HOT compared to CON at t=0 min (63±11 vs. 77±12 mmHg; P=0.005) and t=120 min (72±11 vs.
MD -14Large effectOpen-labelCompleters only
PMID 39209309
Quasi ExperimentalCpositiven=1455% confidence2025
Repeated passive heat treatment increases muscle tissue capillarization, but does not affect postprandial muscle protein synthesis rates in healthy older adults.
average systolic blood pressure was significantly reduced (by 2%; P = 0.019) following 8 weeks of PHT
-2%Trivial effectTop journalOpen-labelNo control groupCompleters only99% dropped outBorderline p-value
PMID 39373667
Expert opinionpositive50% confidence
Regular infrared sauna use is associated with clinically meaningful reductions in systolic and diastolic blood pressure, through improved endothelial function and vasodilation.
Expert knowledge synthesis
Community reportsmoderate effectpositive25% confidence
This effect was mentioned in 2 of 233 Reddit reports discussing it.
2 mentions
Open Blood Pressure Support
→
Stress Resilience ImprovementCertaintyLowSourceClinical1 cited study · 1 other source
A quasi-experimental study in people with Diabetes Type 2 found that self-reported stress and fatigue improved on Visual Analogue Scales.
What the sources found
2 positive · 0 neutral · 0 negativeconfidence 35/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Diabetes Type 2
Where the evidence comes from
Article1
Community reports1
Show studies (2)
Quasi ExperimentalCpositive30% confidence2010
The effects of repeated thermal therapy on quality of life in patients with type II diabetes mellitus.
Visual Analogue Scales for stress and fatigue improved.
Low-quality journalOpen-labelNo control group
PMID 20569036
Community reportssubtle effectpositive40% confidence
This effect was mentioned in 5 of 233 Reddit reports discussing it.
5 mentions
Open Stress Resilience Improvement
→
Increased Growth Hormone ReleaseCertaintyLowSourceClinical1 cited study
In a randomized trial of 10 healthy participants, serum growth hormone increased after both Infrared Sauna and traditional sauna, with the highest levels after sauna and at 30 min of recovery.
What the sources found
1 positive · 0 neutral · 0 negativeconfidence 40/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people
Where the evidence comes from
Article1
Protocol behind this outcome
1 protocolMeasured
What the studies reporting this result did.
30 min
Intensity
Low
Format
Individual
Supervision
Instructor-led
Single sessions · 0 repeated-course and 1 single-session protocols
Timing
A trial found it after a single session
Show studies (1)
RCTCpositiven=1040% confidence2015
Effects of far-infrared sauna bathing on recovery from strength and endurance training sessions in men.
Serum growth hormone increased in both FIRS and in TRAD and was highest (p < 0.05) after sauna and at 30 min of recovery.
Low-quality journalOpen-labelNo control group
PMID 26180741
Open Increased Growth Hormone Release
→
Antioxidant Protection EnhancementCertaintyLowSourceClinical1 cited study · 1 other source
A cross-sectional study reported activation of antioxidant protection by the end of the treatment period.
What the sources found
2 positive · 0 neutral · 0 negativeconfidence 38/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Where the evidence comes from
Article1
Expert opinion1
Show studies (2)
Cross SectionalCpositive25% confidence2013
[The influence of general infrared sauna on the antioxidant systems in the blood of volunteers].
activation of antioxidant protection ... by the end of the treatment period
Main outcomeOpen-labelNo control group
PMID 24437201
Expert opinionpositive50% confidence
Regular infrared sauna use may upregulate endogenous antioxidant defenses, including glutathione and superoxide dismutase, through mild heat stress adaptation.
Expert knowledge synthesis
Open Antioxidant Protection Enhancement
→
Mood ImprovementCertaintyLowSourceClinical1 cited study · 1 other source
A pilot study of 25 healthy participants found a pre-to-post-session reduction in self-reported negative affect (MD -1.72 points [-2.93, -0.51]).
What the sources found
2 positive · 0 neutral · 0 negativeconfidence 43/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people
Where the evidence comes from
Article1
Community reports1
Show studies (2)
Pilot studyCpositiven=2535% confidence2021
Feasibility and acceptability of a Whole-Body hyperthermia (WBH) protocol.
participants evidenced ... reductions (t [24]= -2.93, M diff= -1.72, p =.007, 95% CI [-2.93, -0.51]) in self-reported negative affect pre-post-WBH session
MD -1.72 [-2.93, -0.51]Open-labelNo control group
PMID 34674592
Community reportsmoderate effectpositive50% confidence
This effect was mentioned in 40 of 284 community reports discussing it (Reddit 29, Bluesky 6, YouTube 5).
40 mentions
Open Mood Improvement
→
Weight Management SupportCertaintyLowSourceClinical1 cited study · 1 other source
A 2009 review described support for FIRS therapy in people with obesity, but noted that it came from a single study.
What the sources found
2 positive · 0 neutral · 0 negativeconfidence 20/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people and patients
Chronic Pain
Coronary Artery Disease
Heart Failure (CHF)
Obesity
Where the evidence comes from
Article1
Community reports1
Show studies (2)
Systematic reviewCpositive15% confidence2009
Far-infrared saunas for treatment of cardiovascular risk factors: summary of published evidence.
weak evidence, from a single study, supporting FIRS therapy for obesity
PMID 19602651
Community reportsmoderate effectpositive25% confidence
This effect was mentioned in 2 of 233 Reddit reports discussing it.
2 mentions
Open Weight Management Support
→
Skin Health ImprovementCertaintyLowSourceAnecdotalnot used for recommendations2 other sources
Sweating may open pores, while increased blood flow in the skin may support skin cleansing and nutrient delivery. This effect was mentioned in 8 of 233 community reports.
What the sources found
2 positive · 0 neutral · 0 negativeconfidence 50/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Where the evidence comes from
Expert opinion1
Community reports1
Why it isn't used for recommendations
No supporting study on file
Show studies (2)
Expert opinionpositive50% confidence
Sweating opens pores and increases cutaneous blood flow, which can improve skin cleansing and nutrient delivery, contributing to healthier skin appearance.
Expert knowledge synthesis
Community reportsmoderate effectpositive50% confidence
This effect was mentioned in 8 of 233 Reddit reports discussing it.
8 mentions
Open Skin Health Improvement
→
Heat ToleranceCertaintyLowSourceAnecdotalnot used for recommendations2 other sources
Repeated controlled heat exposure can produce heat acclimation and improve tolerance of later heat exposure; how much Infrared Sauna does so depends on the heat dose. This effect was mentioned in 2 of 233 community reports.
What the sources found
2 positive · 0 neutral · 0 negativeconfidence 38/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Where the evidence comes from
Expert opinion1
Community reports1
Why it isn't used for recommendations
No supporting study on file
Show studies (2)
Expert opinionpositive50% confidence
Repeated controlled heat exposure can induce heat acclimation and improve tolerance of subsequent heat exposure; the extent of this effect with infrared sauna depends on the heat dose.
Expert knowledge synthesis
Community reportsmoderate effectpositive25% confidence
This effect was mentioned in 2 of 233 Reddit reports discussing it.
2 mentions
Open Heat Tolerance
→
Parasympathetic ActivationCertaintyLowSourceTheoreticallong-termnot used for recommendations1 other source
A proposed explanation is that Infrared Sauna may promote vagal tone and shift autonomic balance toward parasympathetic dominance, measurable through increased HRV and a reduced LF/HF ratio.
What the sources found
1 positive · 0 neutral · 0 negativeconfidence 50/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Where the evidence comes from
Expert opinion1
Why it isn't used for recommendations
No supporting study on file
Show studies (1)
Expert opinionpositive50% confidence
Infrared sauna promotes vagal tone and shifts autonomic balance toward parasympathetic dominance, measurable via increased HRV and reduced LF/HF ratio.
Expert knowledge synthesis
Open Parasympathetic Activation
→
Nitric Oxide Production IncreaseCertaintyLowSourceTheoreticalnot used for recommendations1 other source
A proposed mechanism is that heat exposure stimulates endothelial nitric oxide synthase (eNOS), increasing NO bioavailability and contributing to vasodilation and blood pressure reduction.
What the sources found
1 positive · 0 neutral · 0 negativeconfidence 50/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Where the evidence comes from
Expert opinion1
Why it isn't used for recommendations
No supporting study on file
Show studies (1)
Expert opinionpositive50% confidence
Heat exposure from infrared sauna stimulates endothelial nitric oxide synthase (eNOS), increasing NO bioavailability, which mediates vasodilation and blood pressure reduction.
Expert knowledge synthesis
Open Nitric Oxide Production Increase
→
Longevity and Anti-Aging SupportCertaintyLowSourceTheoreticallong-termnot used for recommendations1 other source
Frequent sauna use has been associated with reduced risk of all-cause mortality and cardiovascular death, independent of other lifestyle factors.
What the sources found
1 positive · 0 neutral · 0 negativeconfidence 50/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Where the evidence comes from
Expert opinion1
Why it isn't used for recommendations
No supporting study on file
Show studies (1)
Expert opinionpositive50% confidence
Frequent sauna use is associated with a reduced risk of all-cause mortality and cardiovascular death, independent of other lifestyle factors.
Expert knowledge synthesis
Open Longevity and Anti-Aging Support
→
Physical FunctionCertaintyLowSourceTheoreticalnot used for recommendations1 cited study · 1 other source
Studies did not support improved physical function in people with major depressive disorder: a 2025 randomized trial involving 30 people reported a 3.55-point increase in Physical function 4A, with an interval of [-0.83, 7.92].
What the sources found
1 positive · 1 neutral · 0 negativeconfidence 55/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Major Depressive Disorder
Where the evidence comes from
Article1
Community reports1
Why it isn't used for recommendations
Studied, with no positive result
Show studies (2)
RCTCneutraln=3060% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Physical function 4A: 3.55 (2.23) (–0.83, 7.92)
MD 3.55 [-0.83, 7.92]Sham-controlledSham comparisonCompleters only
PMID 41146956
Community reportsmoderate effectpositive50% confidence
This effect was mentioned in 10 of 233 Reddit reports discussing it.
10 mentions
Open Physical Function
→
Detoxification SupportCertaintyLowSourceTheoreticalLarge effectnot used for recommendations1 cited study · 1 other source
Studies did not support detoxification: a 2020 cohort study involving 255 people reported a non-significant reduction in total mean PAH-OHs of −43.5% (95%CI −68.8%, 2.2%).
What the sources found
1 positive · 1 neutral · 0 negativeconfidence 45/100
How big is the effect
Large effectA big difference on average. Check how strong the evidence is.
Who was studied
Healthy people
Where the evidence comes from
Article1
Community reports1
Why it isn't used for recommendations
Studied, with no positive result
Show studies (2)
Cohort studyCneutraln=25540% confidence2020
Evaluation of Interventions to Reduce Firefighter Exposures.
Sauna treatment non-significantly reduced total mean PAH-OHs by −43.5% (95%CI −68.8%, 2.2%).
-43.5%Large effectMain outcomeOpen-labelInactive control
PMID 31977921
Community reportsmoderate effectpositive50% confidence
This effect was mentioned in 10 of 269 community reports discussing it (Reddit 6, YouTube 4).
10 mentions
Open Detoxification Support
→
Immune System SupportCertaintyLowSourceTheoreticalnot used for recommendations1 cited study · 2 other sources
Immune system support remains theoretical; human evidence has not established this effect.
What the sources found
2 positive · 1 neutral · 0 negativeconfidence 45/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people
Where the evidence comes from
Article1
Expert opinion1
Community reports1
Why it isn't used for recommendations
Studied, with no positive result
Show studies (3)
RCTCneutraln=2040% confidence2025
Comparison of thermoregulatory, cardiovascular, and immune responses to different passive heat therapy modalities.
HWI was the only heating modality to elicit inflammatory and immune responses as evidenced by increased interleukin-6 (IL-6) concentration postheating
Open-label
PMID 40332494
Expert opinionpositive50% confidence
Regular sauna bathing is associated with a reduced incidence of common colds and respiratory infections, possibly via mild hyperthermia and improved immune surveillance.
Expert knowledge synthesis
Community reportsmoderate effectpositive45% confidence
This effect was mentioned in 6 of 233 Reddit reports discussing it.
6 mentions
Open Immune System Support
→
Inflammation ReductionCertaintyLowSourceTheoreticalnot used for recommendations1 cited study · 2 other sources
Inflammation reduction remains theoretical; human evidence has not established this effect.
What the sources found
2 positive · 1 neutral · 0 negativeconfidence 40/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people
Where the evidence comes from
Article1
Expert opinion1
Community reports1
Why it isn't used for recommendations
Studied, with no positive result
Show studies (3)
RCTCneutraln=2040% confidence2025
Comparison of thermoregulatory, cardiovascular, and immune responses to different passive heat therapy modalities.
HWI was the only heating modality to elicit inflammatory and immune responses as evidenced by increased interleukin-6 (IL-6) concentration postheating
Open-label
PMID 40332494
Expert opinionpositive50% confidence
Infrared sauna use reduces systemic inflammation, as evidenced by decreased C-reactive protein and other inflammatory cytokines.
Expert knowledge synthesis
Community reportsmoderate effectpositive30% confidence
This effect was mentioned in 3 of 233 Reddit reports discussing it.
3 mentions
Open Inflammation Reduction
→

	Smallest	Typical
Session	20 min	25 min

	Smallest	Typical
Session	10 min	15 min

Very low probability(6)

Physical Strength IncreaseCertaintyVery lowSourceClinicalnot used for recommendations3 cited studies
Studies did not support an increase in physical strength: a 2025 quasi-experimental study involving 14 people reported 1RM leg strength of 46 ± 12 vs. 47 ± 12 kg (P = 0.087).
What the sources found
0 positive · 3 neutral · 0 negativeconfidence 52/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people
Where the evidence comes from
Article3
Why it isn't used for recommendations
Studied, with no positive result
Show studies (3)
RCTCneutraln=4050% confidence2025
Salivary cortisol response to post-exercise infrared sauna declines over time.
We did not find any differences in CMJ between the groups, indicating that the exercise session induced similar levels fatigue in both groups and post-exercise IRS did not improve the immediate recovery of neuromuscular performance.
Top journalOpen-labelCompleters only
PMID 40926789
Quasi ExperimentalCneutraln=4050% confidence2025
Effects of repeated use of post-exercise infrared sauna on neuromuscular performance and muscle hypertrophy.
There were no time, group, or interaction effects for 20 m sprint, MVC, height of SJ, CMJ, CMJ25%, and CMJ50%, and peak power during CMJ50%
Weak journalOpen-labelCompleters only
PMID 40104529
Quasi ExperimentalCneutraln=1455% confidence2025
Repeated passive heat treatment increases muscle tissue capillarization, but does not affect postprandial muscle protein synthesis rates in healthy older adults.
1RM leg strength (46 ± 12 vs. 47 ± 12 kg; P = 0.087)
Top journalMain outcomeOpen-labelNo control groupCompleters only99% dropped out
PMID 39373667
Open Physical Strength Increase
→
Muscle Mass IncreaseCertaintyVery lowSourceClinicalnot used for recommendations2 cited studies
Studies did not support an increase in muscle mass: a 2025 quasi-experimental study involving 14 people found no change in vastus lateralis muscle CSA (15.3 ± 4.6 vs. 15.2 ± 4.6 cm^2; P = 0.768).
What the sources found
0 positive · 2 neutral · 0 negativeconfidence 53/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people
Where the evidence comes from
Article2
Why it isn't used for recommendations
Studied, with no positive result
Show studies (2)
Quasi ExperimentalCneutraln=4050% confidence2025
Effects of repeated use of post-exercise infrared sauna on neuromuscular performance and muscle hypertrophy.
There was no interaction effect for lean mass, but a time effect (B = 0.43, p = 0.003) was found when lean mass increased in CON [PRE: 44.8 (5.8) kg, POST: 45.5 (6.0) kg, p = 0.050]
Weak journalOpen-labelCompleters only
PMID 40104529
Quasi ExperimentalCneutraln=1455% confidence2025
Repeated passive heat treatment increases muscle tissue capillarization, but does not affect postprandial muscle protein synthesis rates in healthy older adults.
no changes in vastus lateralis muscle CSA (15.3 ± 4.6 vs. 15.2 ± 4.6 cm^2; P = 0.768)
Top journalMain outcomeOpen-labelNo control groupCompleters only99% dropped out
PMID 39373667
Open Muscle Mass Increase
→
Kidney Health SupportCertaintyVery lowSourceClinicalnot used for recommendations1 cited study
The studies did not support improved kidney health. A randomized trial of 10 people with Chronic Kidney Disease found no effect on kidney function or markers of kidney injury.
What the sources found
0 positive · 1 neutral · 0 negativeconfidence 35/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Chronic Kidney Disease
Where the evidence comes from
Article1
Why it isn't used for recommendations
Studied, with no positive result
Show studies (1)
RCTCneutraln=1035% confidence2026
Acute effects of passive heat exposure on vascular function and exercise capacity in patients with chronic kidney disease.
without any effect on kidney function or markers of kidney injury
Top journalOpen-labelSham comparison
PMID 42113470
Open Kidney Health Support
→
Cholesterol Level ReductionCertaintyVery lowSourceClinicalnot used for recommendations1 cited study
Studies did not support cholesterol reduction: a 2009 review of randomized and non-randomized human studies reported consistent fair evidence against claims that infrared sauna reduces cholesterol.
What the sources found
0 positive · 1 neutral · 0 negativeconfidence 25/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people and patients
Chronic Pain
Coronary Artery Disease
Heart Failure (CHF)
Obesity
Where the evidence comes from
Article1
Why it isn't used for recommendations
Studied, with no positive result
Show studies (1)
Systematic reviewCneutral25% confidence2009
Far-infrared saunas for treatment of cardiovascular risk factors: summary of published evidence.
consistent fair evidence to refute claims regarding the role of FIRSs in cholesterol reduction
PMID 19602651
Open Cholesterol Level Reduction
→
Insulin Sensitivity ImprovementCertaintyVery lowSourceTheoreticalnot used for recommendations1 cited study · 1 other source
An improvement in insulin sensitivity remains theoretical; human evidence has not established this effect in people with type 2 diabetes.
What the sources found
1 positive · 1 neutral · 0 negativeconfidence 55/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Diabetes Type 2
Where the evidence comes from
Article1
Expert opinion1
Why it isn't used for recommendations
Studied, with no positive result
Show studies (2)
RCTCneutraln=1260% confidence2024
A Single Sauna Session Does Not Improve Postprandial Blood Glucose Handling in Individuals with Type 2 Diabetes Mellitus: A Cross-Over, Randomized, Controlled Trial.
No differences were observed between HOT and CON for ISI_composite (P=0.67).
MD 0Open-labelCompleters only
PMID 39209309
Expert opinionpositive50% confidence
Heat exposure increases insulin sensitivity via heat shock proteins and improved glucose uptake.
Expert knowledge synthesis
Open Insulin Sensitivity Improvement
→
Mitochondrial Function SupportCertaintyVery lowSourceTheoreticallong-termnot used for recommendations1 cited study · 1 other source
Studies did not support improved mitochondrial function: a 2025 quasi-experimental study involving 14 people observed no changes in muscle mitochondrial content and function after the PHT intervention.
What the sources found
1 positive · 1 neutral · 0 negativeconfidence 50/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people
Where the evidence comes from
Article1
Expert opinion1
Why it isn't used for recommendations
Studied, with no positive result
Show studies (2)
Quasi ExperimentalCneutraln=1450% confidence2025
Repeated passive heat treatment increases muscle tissue capillarization, but does not affect postprandial muscle protein synthesis rates in healthy older adults.
no changes were observed in muscle mitochondrial content and function after the PHT intervention
Top journalOpen-labelNo control groupCompleters only99% dropped out
PMID 39373667
Expert opinionpositive50% confidence
Infrared sauna induces heat shock proteins (HSP70, HSP90), which support mitochondrial repair and biogenesis, improving cellular energy metabolism.
Expert knowledge synthesis
Open Mitochondrial Function Support
→

4 more mentioned only by users

What to expect

Conditions it's used for

Complaints and diagnoses people take it for10 listed

The best we have, but the evidence is still weak

Chronic Fatigue SyndromeCertaintyLowSourceClinical1 cited study · 1 other source
The cited review drew on randomized and non-randomized human studies; the finding does not describe a specific change in chronic fatigue syndrome symptoms.
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people and patients
Chronic Pain
Coronary Artery Disease
Heart Failure (CHF)
Obesity
Where the evidence comes from
Expert opinion
Show studies (2)
Systematic reviewC15% confidence2009
Far-infrared saunas for treatment of cardiovascular risk factors: summary of published evidence.
Weak evidence from a single study (review abstract)
PMID 19602651
Expert opinion50% confidence
Some evidence suggests infrared sauna may alleviate fatigue and improve well-being in chronic fatigue syndrome, possibly through detoxification and improved sleep.
Open Chronic Fatigue Syndrome
→
Chronic PainCertaintyLowSourceClinical1 cited study · 1 other source
A 2009 review drawing on randomized and non-randomized human studies considered people with chronic pain alongside groups with coronary artery disease, heart failure, and obesity.
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people and patients
Chronic Pain
Coronary Artery Disease
Heart Failure (CHF)
Obesity
Where the evidence comes from
Expert opinion
Show studies (2)
Systematic reviewC20% confidence2009
Far-infrared saunas for treatment of cardiovascular risk factors: summary of published evidence.
Fair evidence from a single study (review abstract)
PMID 19602651
Expert opinion50% confidence
Infrared sauna is clinically used to manage chronic low back pain, fibromyalgia, and arthritis-related pain through analgesic and muscle-relaxing effects.
Open Chronic Pain
→
Diabetes Type 2CertaintyLowSourceClinical2 cited studies
A 2010 quasi-experimental study of people with type 2 diabetes reported quality-of-life outcomes.
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Diabetes Type 2
Protocol behind this outcome
1 protocolMeasured
What the studies reporting this result did.
20 min · 3×/week
Course
13 weeks
Per week
60 min
A repeated course
Show studies (2)
RCTCno effectn=1260% confidence2024
A Single Sauna Session Does Not Improve Postprandial Blood Glucose Handling in Individuals with Type 2 Diabetes Mellitus: A Cross-Over, Randomized, Controlled Trial.
Single infrared sauna session did not improve postprandial glucose handling; glucose iAUC was higher after sauna compared to control, with no differences in insulin or insulin sensitivity indices.
Open-labelCompleters only
PMID 39209309
Quasi ExperimentalC30% confidence2010
The effects of repeated thermal therapy on quality of life in patients with type II diabetes mellitus.
Study population selected for type II diabetes; quality of life outcomes reported in this group.
Low-quality journalOpen-labelNo control group
PMID 20569036
Open Diabetes Type 2
→
Hypertension (High Blood Pressure)CertaintyLowSourceClinical1 cited study · 1 other source
A 2009 systematic review of randomized and non-randomized human studies reported possible blood-pressure normalization in populations that included people with chronic pain, coronary artery disease, heart failure, and obesity.
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people and patients
Chronic Pain
Coronary Artery Disease
Heart Failure (CHF)
Obesity
Where the evidence comes from
Expert opinion
Show studies (2)
Systematic reviewC30% confidence2009
Far-infrared saunas for treatment of cardiovascular risk factors: summary of published evidence.
Limited moderate evidence for normalizing blood pressure (review abstract)
PMID 19602651
Expert opinion50% confidence
Regular infrared sauna use is an effective adjunct therapy for lowering blood pressure in hypertensive individuals, due to improved vascular function.
Open Hypertension (High Blood Pressure)
→
Ankylosing SpondylitisCertaintyLowSourceClinical1 cited study
A 2009 single-arm pilot study reported good tolerance and short-term improvements in pain and stiffness among 17 people with ankylosing spondylitis.
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Ankylosing Spondylitis
Rheumatoid Arthritis
Protocol behind this outcome
1 protocolMeasured
What the studies reporting this result did.
Course
4 weeks
A repeated course
Show studies (1)
Pilot studyCn=3435% confidence2009
Infrared sauna in patients with rheumatoid arthritis and ankylosing spondylitis. A pilot study showing good tolerance, short-term improvement of pain and stiffness, and a trend towards long-term beneficial effects.
Pilot single-arm study in 17 AS patients showing good tolerance and short-term pain and stiffness improvement
Open-labelNo control group
PMID 18685882
Open Ankylosing Spondylitis
→
Chronic Kidney DiseaseCertaintyLowSourceClinical1 cited study
A 2026 randomized trial tested acute passive heat exposure in 10 people with chronic kidney disease; the findings were described as informing future trials of chronic heat therapy for cardiovascular health.
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Chronic Kidney Disease
Protocol behind this outcome
1 protocolMeasured
What the studies reporting this result did.
25 min
Format
Individual
Supervision
Instructor-led
Single sessions · 0 repeated-course and 1 single-session protocols
Show studies (1)
RCTCn=1035% confidence2026
Acute effects of passive heat exposure on vascular function and exercise capacity in patients with chronic kidney disease.
Study population of CKD patients in whom acute passive heat exposure was tested; authors describe the findings as informing future chronic heat-therapy trials for CKD cardiovascular health.
Top journalOpen-labelSham comparison
PMID 42113470
Open Chronic Kidney Disease
→
DepressionCertaintyLowSourceClinical1 cited study
A 2025 trial of 30 people with depression found reductions in BDI-II and high remission rates in both the WBH and sham-WBH groups. It was not designed to reliably compare the groups and did not include a CBT-only control.
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Depression
Protocol behind this outcome
1 protocolEstimated
What the studies reporting this result did.
99 min
Course
11 weeks
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (1)
RCTCn=3060% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Both WBH and sham WBH arms showed significant reductions in BDI-II and high rates of remission, but the study was not powered for between-arm comparisons and lacked a CBT-only control.
Sham-controlledSham comparisonCompleters only
PMID 41146956
Open Depression
→

Low probability(3)

ObesityCertaintyLowSourceClinical1 cited study
A 2009 review considered obesity alongside chronic pain, coronary artery disease, and heart failure, drawing on randomized and non-randomized human studies.
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people and patients
Chronic Pain
Coronary Artery Disease
Heart Failure (CHF)
Obesity
Show studies (1)
Systematic reviewC15% confidence2009
Far-infrared saunas for treatment of cardiovascular risk factors: summary of published evidence.
Weak evidence from a single study (review abstract)
PMID 19602651
Open Obesity
→
Rheumatoid ArthritisCertaintyLowSourceClinical1 cited study
A 2009 single-arm pilot study reported good tolerance and short-term improvements in pain and stiffness among 17 people with rheumatoid arthritis.
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Ankylosing Spondylitis
Rheumatoid Arthritis
Protocol behind this outcome
1 protocolMeasured
What the studies reporting this result did.
Course
4 weeks
A repeated course
Show studies (1)
Pilot studyCn=3435% confidence2009
Infrared sauna in patients with rheumatoid arthritis and ankylosing spondylitis. A pilot study showing good tolerance, short-term improvement of pain and stiffness, and a trend towards long-term beneficial effects.
Pilot single-arm study in 17 RA patients showing good tolerance and short-term pain and stiffness improvement
Open-labelNo control group
PMID 18685882
Open Rheumatoid Arthritis
→
FibromyalgiaCertaintyLowSourceTheoreticalnot used for recommendations1 other source
Infrared Sauna may reduce pain, stiffness, and fatigue in people with fibromyalgia.
How big is the effect
No study gave a number we could compare, so the size is not known.
Where the evidence comes from
Expert opinion
Why it isn't used for recommendations
No supporting study on file
Show studies (1)
Expert opinion50% confidence
Infrared sauna reduces pain, stiffness, and fatigue in fibromyalgia patients.
Open Fibromyalgia
→

Side effects

Unwanted effects reported in studies or by users18 listed

Highest probability

Heart Rate IncreaseCertaintyMediumSourceClinical2 cited studies
In a trial involving 40 healthy people, post-session heart rate was 61 ± 8 bpm in the IRS group versus 55 ± 6 bpm in the comparison group. A cohort of 255 also recorded elevated heart rate.
What the sources found
0 not observed · 0 unclear · 2 reportedconfidence 50/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Rating adjusted
Lowered from High to Medium after checking study quality: journal, risk of bias, trial size and design.
Who was studied
Healthy people
Where the evidence comes from
Article2
Protocol behind this outcome
2 protocolsEstimated
What the studies reporting this result did.
15 min · 2.5×/week
Course
6 weeks
Intensity
Low
Format
Individual
Supervision
Instructor-led
Courses and single sessions · 1 repeated-course and 1 single-session protocols
Show studies (2)
RCTCnegativen=4055% confidence2025
Salivary cortisol response to post-exercise infrared sauna declines over time.
The IRS-group showed a higher post-session HR in EX1 compared to the CON-group (61 ± 8 bpm vs. 55 ± 6 bpm; p = 0.019).
MD 6Top journalOpen-labelCompleters onlyBorderline p-value
PMID 40926789
Cohort studyCnegativen=25545% confidence2020
Evaluation of Interventions to Reduce Firefighter Exposures.
Elevated heart rate
Open-labelInactive control
PMID 31977921
Open Heart Rate Increase
→
Fluid Loss (Diuretic Effect)CertaintyMediumSourceClinical1 cited study · 2 other sources
A cohort study in 12 healthy people recorded dehydration with >2% body mass loss.
What the sources found
0 not observed · 0 unclear · 3 reportedconfidence 49/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people
Where the evidence comes from
Article1
Community reports1
Reference knowledge1
Show studies (3)
Cohort studyCnegativen=1245% confidence2026
Far-infrared sauna exposure at 65°C elevates core temperature.
Dehydration >2% body mass loss
Open-labelNo control group
PMID 42533687
Reference knowledgenegative78% confidence
Sweating during a session causes fluid loss; longer or hotter sessions increase the risk of dehydration.
Community reportsnegative25% confidence
This effect was mentioned in 2 of 233 Reddit reports discussing it.
Open Fluid Loss (Diuretic Effect)
→

Low probability(16)

Blood Sugar IncreaseCertaintyLowSourceClinical1 cited study
In a trial involving 12 people with Diabetes Type 2, plasma glucose response during an oral glucose tolerance test was higher after the heated condition than after the thermoneutral condition: 17.7±3.1 versus 14.8±2.8 mmol/L/120 min.
What the sources found
0 not observed · 0 unclear · 1 reportedconfidence 60/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Diabetes Type 2
Where the evidence comes from
Article1
Protocol behind this outcome
1 protocolMeasured
What the studies reporting this result did.
40 min
Format
Individual
Supervision
Instructor-led
Single sessions · 0 repeated-course and 1 single-session protocols
Show studies (1)
RCTCnegativen=1260% confidence2024
A Single Sauna Session Does Not Improve Postprandial Blood Glucose Handling in Individuals with Type 2 Diabetes Mellitus: A Cross-Over, Randomized, Controlled Trial.
The incremental area under the curve (iAUC) of plasma glucose concentrations during the OGTT was higher after the heated condition compared to the thermoneutral condition (17.7±3.1 vs. 14.8±2.8 mmol/L/120 min; P<0.001).
MD 2.9Main outcomeOpen-labelCompleters only
PMID 39209309
Open Blood Sugar Increase
→
Weight GainCertaintyLowSourceClinical1 cited study
A quasi-experimental study in 40 healthy people found body mass increased by 0.9 kg in the IRS group, from 64.8 (7.1) kg before to 65.7 (7.2) kg after the sessions.
What the sources found
0 not observed · 0 unclear · 1 reportedconfidence 50/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
Healthy people
Where the evidence comes from
Article1
Protocol behind this outcome
1 protocolMeasured
What the studies reporting this result did.
10 min · 3×/week
Course
6 weeks
Per week
30 min
Intensity
Low
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (1)
Quasi ExperimentalCnegativen=4050% confidence2025
Effects of repeated use of post-exercise infrared sauna on neuromuscular performance and muscle hypertrophy.
a time effect (B = 0.69, p = 0.003) was observed for body mass which, based on the paired t-tests, increased only in IRS [PRE: 64.8 (7.1) kg, POST: 65.7 (7.2) kg, p = 0.028]
MD 0.9Weak journalOpen-labelCompleters onlyBorderline p-value
PMID 40104529
Open Weight Gain
→
Bruising (Ecchymosis)CertaintyLowSourceClinical1 cited study
A 2025 randomized trial involving 30 people with Major Depressive Disorder recorded bruising.
What the sources found
0 not observed · 0 unclear · 1 reportedconfidence 45/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Major Depressive Disorder
Where the evidence comes from
Article1
Protocol behind this outcome
1 protocolEstimated
What the studies reporting this result did.
99 min
Course
11 weeks
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (1)
RCTCnegativen=3045% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Bruising
Sham-controlledSham comparisonCompleters only
PMID 41146956
Open Bruising (Ecchymosis)
→
Dry MouthCertaintyLowSourceClinical1 cited study
A 2025 randomized trial involving 30 people with Major Depressive Disorder recorded dry mouth.
What the sources found
0 not observed · 0 unclear · 1 reportedconfidence 45/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Major Depressive Disorder
Where the evidence comes from
Article1
Protocol behind this outcome
1 protocolEstimated
What the studies reporting this result did.
99 min
Course
11 weeks
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (1)
RCTCnegativen=3045% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Dry mouth
Sham-controlledSham comparisonCompleters only
PMID 41146956
Open Dry Mouth
→
Mental FatigueCertaintyLowSourceClinical1 cited study
A 2025 randomized trial involving 30 people with Major Depressive Disorder recorded fatigue.
What the sources found
0 not observed · 0 unclear · 1 reportedconfidence 45/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Major Depressive Disorder
Where the evidence comes from
Article1
Protocol behind this outcome
1 protocolEstimated
What the studies reporting this result did.
99 min
Course
11 weeks
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (1)
RCTCnegativen=3045% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Fatigue
Sham-controlledSham comparisonCompleters only
PMID 41146956
Open Mental Fatigue
→
FeverCertaintyLowSourceClinical1 cited study
A trial involving 30 people with Depression listed flu among the reported effects.
What the sources found
0 not observed · 0 unclear · 1 reportedconfidence 45/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Depression
Where the evidence comes from
Article1
Protocol behind this outcome
1 protocolEstimated
What the studies reporting this result did.
99 min
Course
11 weeks
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (1)
RCTCnegativen=3045% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Flu
Sham-controlledSham comparisonCompleters only
PMID 41146956
Open Fever
→
InsomniaCertaintyLowSourceClinical1 cited study
A trial involving 30 people with Depression listed bad sleep among the reported effects.
What the sources found
0 not observed · 0 unclear · 1 reportedconfidence 45/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Depression
Where the evidence comes from
Article1
Protocol behind this outcome
1 protocolEstimated
What the studies reporting this result did.
99 min
Course
11 weeks
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (1)
RCTCnegativen=3045% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Bad sleep
Sham-controlledSham comparisonCompleters only
PMID 41146956
Open Insomnia
→
NauseaCertaintyLowSourceClinical1 cited study
A 2025 randomized trial involving 30 people with Major Depressive Disorder recorded nausea.
What the sources found
0 not observed · 0 unclear · 1 reportedconfidence 45/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Major Depressive Disorder
Where the evidence comes from
Article1
Protocol behind this outcome
1 protocolEstimated
What the studies reporting this result did.
99 min
Course
11 weeks
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (1)
RCTCnegativen=3045% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Nausea
Sham-controlledSham comparisonCompleters only
PMID 41146956
Open Nausea
→
Temperature SensitivityCertaintyLowSourceClinical1 cited study
A trial involving 30 people with Depression listed chills among the reported effects.
What the sources found
0 not observed · 0 unclear · 1 reportedconfidence 45/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Depression
Where the evidence comes from
Article1
Protocol behind this outcome
1 protocolEstimated
What the studies reporting this result did.
99 min
Course
11 weeks
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (1)
RCTCnegativen=3045% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Chills
Sham-controlledSham comparisonCompleters only
PMID 41146956
Open Temperature Sensitivity
→
VomitingCertaintyLowSourceClinical1 cited study
A 2025 randomized trial involving 30 people with Major Depressive Disorder recorded vomiting.
What the sources found
0 not observed · 0 unclear · 1 reportedconfidence 45/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Major Depressive Disorder
Where the evidence comes from
Article1
Protocol behind this outcome
1 protocolEstimated
What the studies reporting this result did.
99 min
Course
11 weeks
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (1)
RCTCnegativen=3045% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Vomiting
Sham-controlledSham comparisonCompleters only
PMID 41146956
Open Vomiting
→
HeadacheCertaintyLowSourceClinical1 cited study · 1 other source
A 2025 randomized trial involving 30 people with Major Depressive Disorder recorded headache.
What the sources found
0 not observed · 0 unclear · 2 reportedconfidence 38/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Major Depressive Disorder
Where the evidence comes from
Article1
Community reports1
Protocol behind this outcome
1 protocolEstimated
What the studies reporting this result did.
99 min
Course
11 weeks
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (2)
RCTCnegativen=3045% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Headache
Sham-controlledSham comparisonCompleters only
PMID 41146956
Community reportsnegative30% confidence
This effect was mentioned in 3 of 233 Reddit reports discussing it.
Open Headache
→
DizzinessCertaintyLowSourceClinical1 cited study · 1 other source
A 2025 randomized trial involving 30 people with Major Depressive Disorder recorded lightheadedness.
What the sources found
0 not observed · 0 unclear · 2 reportedconfidence 33/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Major Depressive Disorder
Where the evidence comes from
Article1
Community reports1
Protocol behind this outcome
1 protocolEstimated
What the studies reporting this result did.
99 min
Course
11 weeks
Intensity
High
Format
Individual
Supervision
Instructor-led
A repeated course
Show studies (2)
RCTCnegativen=3040% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Lightheadedness
Sham-controlledSham comparisonCompleters only
PMID 41146956
Community reportsnegative25% confidence
This effect was mentioned in 2 of 233 Reddit reports discussing it.
Open Dizziness
→
PainCertaintyLowSourceClinical1 cited study · 1 other source
A 2025 randomized trial involving 30 people with Major Depressive Disorder recorded stomach pain.
What the sources found
0 not observed · 0 unclear · 2 reportedconfidence 33/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Who was studied
People with a condition
Major Depressive Disorder
Where the evidence comes from
Article1
Community reports1
Show studies (2)
RCTCnegativen=3040% confidence2025
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).
Stomach pain
Sham-controlledSham comparisonCompleters only
PMID 41146956
Community reportsnegative25% confidence
This effect was mentioned in 2 of 233 Reddit reports discussing it.
Open Pain
→
Blood Pressure DecreaseCertaintyLowSourceReference knowledge1 other source
Heat-induced widening of blood vessels can lower blood pressure during or after a session, especially when standing; this is described in pharmacology references.
What the sources found
0 not observed · 0 unclear · 1 reportedconfidence 75/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Where the evidence comes from
Reference knowledge1
Show studies (1)
Reference knowledgenegative75% confidence
Heat-induced vasodilation can lower blood pressure during or after a session, especially when standing.
Open Blood Pressure Decrease
→
Fainting (Syncope)CertaintyLowSourceReference knowledge1 other source
Heat-related widening of blood vessels and fluid loss can contribute to fainting, particularly when leaving the sauna or standing quickly.
What the sources found
0 not observed · 0 unclear · 1 reportedconfidence 72/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Where the evidence comes from
Reference knowledge1
Show studies (1)
Reference knowledgenegative72% confidence
Heat-related vasodilation and fluid loss can cause fainting, particularly when leaving the sauna or standing quickly.
Open Fainting (Syncope)
→
Heat IllnessCertaintyLowSourceReference knowledge2 other sources
Excessive heat exposure or prolonged sessions can cause heat illness. People also reported this effect in community reports.
What the sources found
0 not observed · 0 unclear · 2 reportedconfidence 49/100
How big is the effect
No study gave a number we could compare, so the size is not known.
Where the evidence comes from
Community reports1
Reference knowledge1
Show studies (2)
Reference knowledgenegative72% confidence
Excessive heat exposure or prolonged sessions can cause heat illness.
Community reportsnegative25% confidence
This effect was mentioned in 2 of 233 Reddit reports discussing it.
Open Heat Illness
→

3 more mentioned only by users

Don't do it if

When to skip it or get medical advice first10 listed

Highest probability

Acute Febrile IllnessCertaintyLowSourceReference knowledgeTheoretical
Adding external heat during an active fever can overwhelm the body’s temperature regulation and lead to dangerous overheating or cardiovascular collapse.
Where the evidence comes from
Reference knowledge
Confidence
confidence 80/100
Rationale
Adding external heat during an active fever can overwhelm thermoregulation, leading to dangerous hyperthermia and cardiovascular collapse.
Open Acute Febrile Illness
→
Heart ArrhythmiaCertaintyLowSourceReference knowledgeTheoretical
The rise in heart rate and sympathetic activity during sauna use may trigger or worsen symptomatic or uncontrolled arrhythmias, including atrial fibrillation with rapid ventricular response.
Where the evidence comes from
Reference knowledge
Confidence
confidence 83/100
Rationale
Infrared sauna increases heart rate and sympathetic tone, which can trigger or exacerbate symptomatic or uncontrolled arrhythmias such as atrial fibrillation with rapid ventricular response.
Open Heart Arrhythmia
→
Orthostatic HypotensionCertaintyLowSourceReference knowledgeTheoretical
Sauna-related widening of blood vessels and fluid shifts can worsen blood pressure drops on standing, increasing the risk of falls or fainting.
Where the evidence comes from
Reference knowledge
Confidence
confidence 80/100
Rationale
Infrared sauna induces peripheral vasodilation and fluid shift, which can worsen orthostatic hypotension and increase fall and syncope risk upon standing.
Open Orthostatic Hypotension
→
PregnancyCertaintyLowSourceReference knowledgeTheoretical
Maternal overheating, especially in the first trimester, is associated with increased risk of neural tube defects and other adverse fetal outcomes.
In the trials
1 trial of this practice also left out people with this condition. That does not show harm.
PubMed links (1)
PMID 41146956
Where the evidence comes from
Reference knowledge
Confidence
confidence 85/100
Rationale
Maternal hyperthermia, especially in the first trimester, is associated with an increased risk of neural tube defects and other adverse fetal outcomes.
Open Pregnancy
→
Recent Heart Attack (MI)CertaintyLowSourceReference knowledgeTheoretical
During early recovery from a heart attack, heat-related increases in heart rate and cardiac output can raise the risk of arrhythmia or ischemia.
Where the evidence comes from
Reference knowledge
Confidence
confidence 85/100
Rationale
Acute myocardial infarction creates vulnerability to thermal stress; heat-induced tachycardia and increased cardiac output can precipitate arrhythmias or ischemia in early recovery.
Open Recent Heart Attack (MI)
→
Acute Kidney InjuryCertaintyLowSourceReference knowledgeTheoretical
Sweating can reduce blood flow to the kidneys; with acute kidney injury, the resulting fluid depletion and increased metabolic demand may worsen low urine output and delay recovery.
Where the evidence comes from
Reference knowledge
Confidence
confidence 78/100
Rationale
Sweating reduces renal perfusion; in acute kidney injury, this can worsen oliguria and delay recovery due to volume depletion and increased metabolic demand.
Open Acute Kidney Injury
→
AnginaCertaintyLowSourceReference knowledgeTheoretical
Unstable angina signals active reduced blood flow to the heart, and the added cardiovascular demand from heat may worsen ischemia.
Where the evidence comes from
Reference knowledge
Confidence
confidence 78/100
Rationale
Unstable angina indicates active myocardial ischemia; heat-related cardiovascular demand can worsen ischemia.
Open Angina
→

Low probability(3)

Heart Failure (CHF)CertaintyLowSourceReference knowledgeTheoretical
With decompensated heart failure or current fluid overload, the heat-related increase in cardiac workload and fluid loss may be unsafe; sauna use is best avoided until the condition is clinically stable.
Where the evidence comes from
Reference knowledge
Confidence
confidence 78/100
Rationale
Decompensated heart failure or current volume overload can make the heat-related rise in cardiac workload and fluid loss unsafe; avoid sauna until clinically stable.
Open Heart Failure (CHF)
→
Multiple SclerosisCertaintyLowSourceReference knowledgeTheoretical
Heat exposure can temporarily worsen neurological symptoms in many people with multiple sclerosis, a response known as Uhthoff’s phenomenon, and may be disabling.
Where the evidence comes from
Reference knowledge
Confidence
confidence 75/100
Rationale
Many MS patients experience Uhthoff's phenomenon—a temporary worsening of neurological symptoms with heat exposure—making sauna use potentially disabling.
Open Multiple Sclerosis
→
Hypotension (Low Blood Pressure)CertaintyLowSourceReference knowledgeTheoretical
Sauna-related widening of blood vessels can further lower blood pressure in people with pre-existing low blood pressure, potentially causing fainting and injury.
Where the evidence comes from
Reference knowledge
Confidence
confidence 70/100
Rationale
Infrared sauna causes significant vasodilation; in individuals with pre-existing low blood pressure, this can lead to severe hypotension, syncope, and injury.
Open Hypotension (Low Blood Pressure)
→

Who the trials left out

Some trials of this practice did not take people with these conditions, so the studies say less about them. This is not a warning and does not show harm. Ask a clinician first.3 listed

Left out by one trial each (3)

Heart Disease (General)left out by 1 trial
PubMed links (1)
PMID 39373667
Kidney Disease (General)left out by 1 trial
PubMed links (1)
PMID 39373667
Pregnancyleft out by 1 trialAlso in “Don't do it if”
PubMed links (1)
PMID 41146956

Interactions

What changes when it is combined with something else

Combine with caution

Highest severity first

CaffeineTheoreticalCaution
Caffeine increases core body temperature and heart rate; with Infrared Sauna, this may add to hyperthermia, dehydration, and cardiovascular strain, especially for heat-sensitive people.
Where the evidence comes from
Reference knowledge
Confidence
confidence 80/100
Open Caffeine
→
Thiazide DiureticsTheoreticalCaution
Thiazide Diuretics can impair fluid retention and electrolyte balance. Combined with sweating during Infrared Sauna, this can increase the risk of hypovolemia, hypotension, and arrhythmias.
Where the evidence comes from
Reference knowledge
Confidence
confidence 82/100
Open Thiazide Diuretics
→
SupplementsArginineTheoreticalCaution
Arginine promotes blood-vessel widening; combined with the widening caused by heat, it may lead to excessive hypotension, dizziness, or fainting.
Where the evidence comes from
Reference knowledge
Confidence
confidence 70/100
Open Arginine
→
SupplementsBeta-AlanineTheoreticalCaution
Beta-Alanine can cause tingling that may be intensified during Infrared Sauna exposure and mistaken for heat intolerance or neurological distress.
Where the evidence comes from
Reference knowledge
Confidence
confidence 70/100
Open Beta-Alanine
→

Okay to combine with

AllSupplementsPractices

Highest probability of useful synergy

SupplementsMagnesiumCertaintyMediumSourceReference knowledgeComplementary
A pharmacology reference describes Magnesium as helping offset losses through sweat and supporting muscle relaxation, cramp prevention, and cardiovascular stability during repeated sauna use.
Where the evidence comes from
Reference knowledge
Confidence
confidence 70/100
Open Magnesium
→
PracticesStatic StretchingCertaintyMediumSourceReference knowledgePotentiating
A pharmacology reference describes Static Stretching after a sauna as taking advantage of increased tissue elasticity and blood flow, which may improve flexibility and reduce injury risk.
Where the evidence comes from
Reference knowledge
Confidence
confidence 68/100
Open Static Stretching
→
PracticesIce Bath / Cold PlungeCertaintyMediumSourceReference knowledgeComplementary
A pharmacology reference describes alternating an infrared sauna with cold immersion as enhancing circulatory pump effects and helping reduce muscle soreness and improve recovery.
Where the evidence comes from
Reference knowledge
Confidence
confidence 65/100
Open Ice Bath / Cold Plunge
→
PracticesMeditationCertaintyMediumSourceReference knowledgeAdditive
A pharmacology reference describes Meditation during or after an infrared sauna as supporting parasympathetic activation, deeper relaxation, and stress resilience.
Where the evidence comes from
Reference knowledge
Confidence
confidence 65/100
Open Meditation
→

Weakens or is weakened by

AllSupplementsPractices

Highest probability

SupplementsEthanol (Alcohol)CertaintyMediumSourceReference knowledgeDepleting
Alcohol can impair temperature regulation, increase dehydration, and depress central nervous system function, potentially counteracting sauna’s cardiovascular and cognitive benefits while increasing fainting risk.
Where the evidence comes from
Reference knowledge
Confidence
confidence 75/100
Open Ethanol (Alcohol)
→
PracticesCardioCertaintyMediumSourceReference knowledgeCompetitive
High-intensity cardio immediately before or after an infrared sauna can add cardiovascular strain and increase the risk of low blood pressure or an arrhythmia; separating the timing is important.
Where the evidence comes from
Reference knowledge
Confidence
confidence 70/100
Open Cardio
→

How it works

The mechanisms this practice works through17 listed · 0 established

Blood antioxidant protectionAntioxidant defenceproposed
Heat exposure induces oxidative stress followed by activation of antioxidant protection.
PMID 24437201
Body core and skin temperatureThermoregulatory responseproposed
Infrared sauna bathing increased tympanic and skin temperature, and heart rate, indicating a thermoregulatory response.
PMID 39209309
Core body temperatureThermoregulatoryproposed
WBH raises core body temperature to 38.5°C, potentially stimulating thermoregulatory cooling responses and afferent neural signaling that may improve mood.
PMID 41146956
Cortisol responseHypothalamic-pituitary-adrenal (HPA) axisproposed
After six weeks of regular post-exercise IRS use, the cortisol response to exercise was blunted, indicating adaptation of the HPA axis to the heat intervention.
PMID 40926789
Endothelium-independent vasodilationVascular toneproposed
Vasodilation developing by the end of the treatment period, proposed as a compensatory-adaptive reaction supporting thermoregulation.
PMID 24437201
Leg musclesNeuromuscular recoveryproposed
Infrared heat penetrates deeply (3-4 cm) into fat tissue and neuromuscular system, potentially improving force production and relaxation of leg muscles after endurance exercise.
PMID 26180741
Muscle growthmTOR signalingproposed
Heat exposure may activate mTOR kinases, stimulating cell growth and potentially contributing to hypertrophy.
PMID 40104529
Muscle hypertrophyHeat shock protein (HSP) expressionproposed
Heat exposure may increase HSP expression, which protects cells, enhances muscle regeneration, and promotes hypertrophy, but requires muscle temperatures of 38°C or higher.
PMID 40104529
Nocturnal heart rateAutonomic nervous system (ANS)proposed
The higher nocturnal heart rate observed after the first IRS session was not present after six weeks, suggesting adaptation of the autonomic nervous system to the heat intervention.
PMID 40926789
Noradrenaline and cortisolStress hormone responseproposed
Infrared sauna bathing increased plasma noradrenaline and cortisol concentrations immediately after the session, suggesting a systemic stress response.
PMID 39209309
Postprandial glucose handlingGlucose metabolismproposed
8 weeks of PHT lowered postprandial plasma glucose iAUC.
PMID 39373667
Skeletal muscle capillariesAngiogenesisproposed
8 weeks of PHT increased type I and type II muscle fiber capillarization (CFPE index +31% and +33%, respectively).
PMID 39373667
Systolic blood pressureCardiovascularproposed
8 weeks of PHT reduced systolic blood pressure by 2%.
PMID 39373667
Urinary PAH-OH excretionDetoxificationproposed
Infrared sauna treatment was hypothesized to increase excretion of PAH metabolites through sweat, but the reduction in urinary PAH-OHs was not statistically significant.
PMID 31977921
core (tympanic) temperaturethermoregulationproposed
Infrared sauna raised tympanic temperature relative to control in healthy women; the authors attribute the sauna's physiological effects primarily to thermoregulatory responses rather than exercise-like cardiorespiratory activation.
PMID 34954348
core temperature and cardiac outputsystemic heat stress responseproposed
FIR sauna raised core temperature and cardiac output less than HWI or TRAD in this study; FIR produced no reported significant inflammatory or immune response.
PMID 40332494
flow-mediated dilation (brachial artery)vascular endothelial functionproposed
Acute passive heat exposure increased FMD relative to thermoneutral control in CKD participants.
PMID 42113470

Variations

Which version to do, and how much of it4 documented

Typical protocol

17 protocolsEstimated

Across every study of this practice, whatever the variation.

28 min · 3×/week

Course: 6 weeks
Temperature: 49–60 °C
Humidity: 19–30%
Rounds: 1–4
Intensity: Low
Format: Individual
Supervision: Instructor-led

Courses and single sessions · 7 repeated-course and 10 single-session protocols

90% of the corpus contributed

Standard Post-Workout Recovery

Beginner9/1015–20 min · 3 times a week

15–20 min · 3 times a week

From studies

How often: 3 times a week
Intensity: Low
Time of day: Any time
Where: Indoors
Research depth: Moderate

This variation is framed around muscle relaxation and reduced soreness between training sessions, with an emphasis on avoiding excessive thermal stress.

No equipment needed.

not for children,not in pregnancy

As studied

6 protocolsEstimated

The protocol the studies of this variation actually used.

10–20 min

Course: 6 weeks
Longest single session studied: 30 min
Temperature: 42.5–43 °C
Humidity: 21–30%
Rounds: 1
Intensity: Low
Format: Individual
Supervision: Instructor-led

Courses and single sessions · 3 repeated-course and 3 single-session protocols

Derived from20569036 26180741 31977921 37398966 40104529 +1 more in Sources

How it's done7 steps · 3 cues · 3 common mistakes

A general description of the practice, not instruction or medical advice.

Steps

Hydrate with 300-500ml of water before entering the sauna.
Set the infrared sauna temperature to 45-50°C (113-122°F).
Enter the sauna wearing light, breathable clothing like shorts and a sports bra or a cotton t-shirt.
Sit comfortably on the bench with your back straight and feet flat on the floor.
Relax for 20 minutes, breathing normally. You should feel a gentle, deep warmth but not be sweating profusely.
Exit the sauna slowly and cool down at room temperature for 5-10 minutes.
Rehydrate with another 300-500ml of water.

Cues

· Focus on nasal breathing
· Keep shoulders relaxed and away from ears
· The goal is a light sweat, not overheating

Common mistakes

Staying in too long and becoming lightheaded
Not drinking enough water beforehand
Wearing heavy, non-breathable clothing

Studied protocols6 on file

20 min· 3×/week· 13 weeks· A repeated coursePMID 20569036
10 min· 3×/week· 6 weeks· n=40· A repeated coursePMID 40104529
10 min· 2.5×/week· 6 weeks· n=40· A repeated coursePMID 40926789
30 min· 42.5 °C, 30%, Rounds 1· n=10· Single sessionsPMID 26180741
20 min· n=255· Single sessionsPMID 31977921
20 min· 43 °C, 21%, Rounds 1· n=16· Single sessionsPMID 37398966

Gentle Evening Relaxation

Beginner8/1010–20 min · As needed

10–20 min · As needed

Editorial

How often: As needed
Intensity: Very low
Time of day: Before bed
Where: Indoors
Research depth: Minimal

This brief, mild-heat session is intended as a calming wind-down before bed, with slow breathing and a focus on relaxing tense muscles. The guidance cautions that too much heat or a session that runs too long may leave you overheated at bedtime.

No equipment needed.

not for children,not in pregnancy

How it's done7 steps · 3 cues · 3 common mistakes

A general description of the practice, not instruction or medical advice.

Steps

Dim the lights in the sauna room or use a sauna with chromotherapy lighting set to red or no light.
Set the temperature to a very mild 35-45°C (95-113°F).
Enter the sauna and sit or lie down in a comfortable position.
Close your eyes and practice slow, deep breathing: inhale for 4 counts, hold for 2, exhale for 6.
Stay in the sauna for 15 minutes. The heat should feel soothing, not challenging.
Exit the sauna and wrap yourself in a warm robe. Avoid screens and bright lights.
Proceed directly to your bedtime routine.

Cues

· Soften your jaw and the space between your eyebrows
· Imagine the heat melting away tension from your muscles
· Keep the session short to avoid raising your core temperature too much, which can disrupt sleep

Common mistakes

Setting the temperature too high, which is stimulating rather than relaxing
Using a phone or tablet during the session
Staying in too long and feeling overheated at bedtime

Studied protocols2 on file

15 min· 5×/week· 3 weeks· 60 °C· A repeated coursePMID 30239008
15 min· n=16· Single sessionsPMID 34632485

Extended Heat Adaptation

Intermediate7/1035–50 min · 3 times a week

35–50 min · 3 times a week

Editorial

How often: 3 times a week
Intensity: High
Time of day: First half of the day
Where: Indoors
Research depth: Minimal

This variation is intended to build heat tolerance and support cardiovascular function through longer, hotter exposure that raises core body temperature. It is described for healthy individuals seeking endurance gains or heat acclimatization, with gradual build-up and careful hydration.

No equipment needed.

not for children,not in pregnancy,caution for older adults

As studied

6 protocolsMeasured

The protocol the studies of this variation actually used.

45 min

Course: 8 weeks
Temperature: 45–65 °C
Humidity: 19%
Rounds: 1
Format: Individual
Supervision: Instructor-led

Courses and single sessions · 1 repeated-course and 5 single-session protocols

Derived from34954348 39209309 39373667 40332494 42113470 +1 more in Sources

How it's done7 steps · 3 cues · 3 common mistakes

A general description of the practice, not instruction or medical advice.

Steps

Ensure you are well-hydrated throughout the day before the session.
Set the infrared sauna to 55-65°C (131-149°F).
Enter the sauna and sit upright. It is normal to not sweat immediately as infrared heat penetrates deeply.
Start with a 10-minute warm-up phase at a lower temperature if your sauna allows, or simply sit for the first 10 minutes acclimating.
Remain in the sauna for a total of 40-45 minutes. If you feel dizzy or nauseous, exit immediately.
After exiting, take a lukewarm shower to gradually bring your body temperature down.
Drink an electrolyte beverage or water with a pinch of salt to replenish minerals lost through heavy sweating.

Cues

· Monitor your heart rate; it should feel like a brisk walk
· Place a small towel on the bench to absorb sweat
· Keep the session to the first half of the day to avoid sleep disruption

Common mistakes

Attempting a long, hot session without prior acclimation
Ignoring early signs of heat exhaustion like headache or nausea
Taking a cold shower immediately after, which can cause a sudden blood pressure drop

Studied protocols6 on file

45 min· 3×/week· 8 weeks· n=14· A repeated coursePMID 39373667
45 min· Rounds 1· n=10· Single sessionsPMID 34954348
40 min· n=12· Single sessionsPMID 39209309
45 min· 45–65 °C· n=20· Single sessionsPMID 40332494
25 min· 60 °C· n=10· Single sessionsPMID 42113470
45 min· 65 °C, 19%· n=12· Single sessionsPMID 42533687

Clinical Whole-Body Hyperthermia

Expert5/10supervision recommended60–100 min · Weekly

60–100 min · Weekly

Editorial

How often: Weekly
Intensity: Very high
Time of day: First half of the day
Where: Indoors
Research depth: Minimal

This is a medically supervised hyperthermia protocol intended for therapeutic use, including as an adjunct for mood disorders—not a home relaxation session. It uses core-temperature monitoring and supervised cooling, and requires medical screening and clearance.

Equipment: Medical-grade infrared sauna dome or whole-body system, Core temperature monitoring device, Blood pressure monitor

not for children,not in pregnancy,caution for older adults

How it's done7 steps · 3 cues · 3 common mistakes

A general description of the practice, not instruction or medical advice.

Steps

Undergo a pre-session medical screening to rule out contraindications.
Hydrate with a specific electrolyte protocol as directed by the supervising clinician.
Lie down in the infrared sauna dome with your head outside the heated area.
Allow the clinician to insert a core temperature monitoring probe.
The sauna is heated until your core temperature reaches approximately 38.5°C (101.3°F), which may take 60-90 minutes.
Core temperature is maintained at the target for a prescribed duration under constant supervision.
Begin a supervised, gradual cooling-down process immediately after the heating phase is complete.

Cues

· This is a medical procedure, not a relaxation technique
· Communicate any unusual sensations to the supervisor immediately
· Mental focus should be on staying calm and still

Common mistakes

Attempting this protocol at home without medical supervision
Failing to disclose all medications and health conditions during screening
Standing up too quickly after the session, risking orthostatic hypotension

Studied protocols3 on file

99 min· 11 weeks· 57.2 °C, Rounds 4· n=30· A repeated coursePMID 41146956
4 weeks· Rounds 8· n=34· A repeated coursePMID 18685882
110 min· n=25· Single sessionsPMID 34674592

How to start

Community experience

What people say they do — not evidence

Based on 319 public posts from Reddit, YouTube, Phoenix Rising, Bluesky, and Hacker News.

Signal found76 signals5 platforms

Reddit 233YouTube 36Phoenix Rising 27Bluesky 15Hacker News 8

What people report it did

22 outcomes mentioned across 319 public reports. A report often mentions several, so these counts do not add up to the total.

Reported benefits18

Mood Improvement45 mentions
Sleep Quality Improvement33 mentions
Chronic Pain Reduction33 mentionsnot studied
Muscle Recovery Acceleration17 mentions
Physical Energy Increase17 mentions
Detoxification Support17 mentions
Cellular Energy Support13 mentionsnot studied
Skin Health Improvement10 mentions
Physical Endurance Increase10 mentions
Physical Function10 mentions
Immune System Support9 mentions
Anxiety Reduction8 mentions
Muscle Soreness Reduction (DOMS)8 mentions
Biorhythm Regulation6 mentionsnot studied
Blood Flow Improvement5 mentions
Sleep Onset Improvement5 mentionsnot studied
Stress Resilience Improvement5 mentions
Cardiovascular Health Support5 mentions

Reported side effects3

Physical Fatigue6 mentionsnot studied
Paresthesia (Tingling/Numbness)not studied
Skin Rash / Irritationnot studied

Reported after stopping1

Physical Endurance Decreasenot studied

What people report doing

Counted from public posts and videos, not from a survey. Each figure counts the posts that mentioned it — most reports say nothing about schedule.

Where7 mentions

At home4Studio3

Session lengthas written

“25 minutes”“30 minutes”“3 hours”

How long they've practisedas written

“2 weeks”

References

22 screened · 19 analysed · 20 listed below

Studies and sources cited on this page. Evidence quality varies — check the grade on each.

Effects of sauna bath on heart failure: A systematic review and meta-analysis.Clin Cardiol2018Meta-analysisB
Acute effects of passive heat exposure on vascular function and exercise capacity in patients with chronic kidney disease.Am J Physiol Heart Circ Physiol2026Crossover RCTCn=10
Far-infrared sauna exposure at 65°C elevates core temperature.Exp Physiol2026Observational CohortCn=12
Salivary cortisol response to post-exercise infrared sauna declines over time.Temperature (Austin)2025RCTCn=40
Repeated passive heat treatment increases muscle tissue capillarization, but does not affect postprandial muscle protein synthesis rates in healthy older adults.J Physiol2025Quasi ExperimentalCn=14
Effects of repeated use of post-exercise infrared sauna on neuromuscular performance and muscle hypertrophy.Front Sports Act Living2025Quasi ExperimentalCn=40
A Randomized Trial Testing a Novel Mind and Body Intervention for Depression: Cognitive Behavioral Therapy (CBT) and Whole-Body Hyperthermia (WBH).Glob Adv Integr Med Health2025RCTCn=30
Comparison of thermoregulatory, cardiovascular, and immune responses to different passive heat therapy modalities.Am J Physiol Regul Integr Comp Physiol2025Crossover RCTCn=20
A Single Sauna Session Does Not Improve Postprandial Blood Glucose Handling in Individuals with Type 2 Diabetes Mellitus: A Cross-Over, Randomized, Controlled Trial.Exp Clin Endocrinol Diabetes2024Crossover RCTCn=12
A post-exercise infrared sauna session improves recovery of neuromuscular performance and muscle soreness after resistance exercise training.Biol Sport2023Crossover RCTCn=16

Show all 20 references

Infrared sauna as exercise-mimetic? Physiological responses to infrared sauna vs exercise in healthy women: A randomized controlled crossover trial.2022Crossover RCTCn=10
Autonomic Nervous System Response to Far-Infrared Sauna Exposure in Firefighters.2022Quasi ExperimentalCn=16
Feasibility and acceptability of a Whole-Body hyperthermia (WBH) protocol.2021Pilot studyCn=25
Evaluation of Interventions to Reduce Firefighter Exposures.2020Observational CohortCn=255
Effects of far-infrared sauna bathing on recovery from strength and endurance training sessions in men.2015Crossover RCTCn=10
[The influence of general infrared sauna on the antioxidant systems in the blood of volunteers].2013Observational Cross SectionalC
The effects of repeated thermal therapy on quality of life in patients with type II diabetes mellitus.2010Quasi ExperimentalC
Infrared sauna in patients with rheumatoid arthritis and ankylosing spondylitis. A pilot study showing good tolerance, short-term improvement of pain and stiffness, and a trend towards long-term beneficial effects.2009Pilot studyCn=34
Far-infrared saunas for treatment of cardiovascular risk factors: summary of published evidence.2009Systematic reviewC
Expert knowledge synthesis