Quality of evidence: A search of Web of Science, EBSCO, Ovid MEDLINE, Ovid HealthSTAR, and EMBASE using the terms far-infrared and sauna, refined by limiting the search to studies of humans published in English, yielded 9 relevant papers (level I or level II evidence).
Main message: Far-infrared saunas are approved by the Canadian Standards Association and are sold to the public. The manufacturers claim numerous health benefits; however, the published evidence to substantiate these claims is limited. Four papers support the use of FIRS therapy for those with congestive heart failure and 5 papers support its use for those with coronary risk factors.
Conclusion: There is limited moderate evidence supporting FIRS efficacy in normalizing blood pressure and treating congestive heart failure; fair evidence, from a single study, supporting FIRS therapy in chronic pain; weak evidence, from a single study, supporting FIRS therapy in chronic fatigue syndrome; weak evidence, from a single study, supporting FIRS therapy for obesity; and consistent fair evidence to refute claims regarding the role of FIRSs in cholesterol reduction.
Beever R. Far-infrared saunas for treatment of cardiovascular risk factors: summary of published evidence. Can Fam Physician. 2009 Jul;55(7):691-6. PMID: 19602651; PMCID: PMC2718593.