Saunas and Steam Rooms: Traditional, Infrared and Steam

A Related Heat Practice, Not Water Immersion

Saunas and steam rooms heat the air around you. You are not immersed in water, so they are related thermal practices rather than hydrotherapy in the strict sense. They are covered here because spas and wellness centers offer them alongside baths and plunge pools, and because many of the same safety issues, such as fainting and dehydration, apply. For a direct comparison, see sauna vs steam room.

Traditional Sauna

A traditional sauna is a heated room, usually wood-lined, with very dry hot air. Sauna bathing has long been part of everyday life in Finland, and most of the best long-term data come from there. This is cultural context to keep in mind: Finnish participants have often used saunas since childhood, which may affect whether results apply elsewhere. [1]

What the research shows:

• Cardiovascular outcomes, observational. In a Finnish study of 2,315 middle-aged men followed for a median of 20.7 years, men who used a sauna 4 to 7 times a week had a lower risk of sudden cardiac death than men who used one once a week (hazard ratio 0.37). The authors concluded sauna bathing is associated with lower risk, and called for more studies to establish a mechanism. [2] This kind of study shows an association, not cause and effect; people who sauna often may differ in other ways. A 2019 review described the evidence as uncertain, with plausible mechanisms still being studied. [3] Label: promising but limited.
• Broader reviews. A systematic review of 40 clinical studies (3,855 participants) found most reported beneficial effects, but only 13 were randomized controlled trials and most were small. The authors said medical evidence for many claims is not well established. [4]
• Blood pressure. A review of heat-based interventions found short-term blood pressure drops, but long-term benefit is unproven. [5] Label: insufficient evidence for a lasting effect.
• Joint pain and respiratory symptoms. A 2001 review suggested sauna may ease pain and improve joint mobility in rheumatic disease, though more data were needed. [6]

Infrared Sauna

Infrared saunas use infrared heaters that warm the body directly rather than mainly heating the air. Most of the human research on them is in people with heart failure. A meta-analysis of 7 studies found infrared sauna was associated with short-term improvement in heart function in those patients, with the strength of evidence ranging from moderate to insufficient. Only infrared studies met its criteria. [7] Label: insufficient evidence for healthy people. Claims that infrared saunas are superior to traditional saunas for general wellness are marketing claims: proper evidence not found in the systematic reviews read, which did not compare them directly.

Steam Rooms

A steam room is a very humid heated room. A PubMed search for trials of steam rooms and steam baths turned up no usable human outcome studies, so for specific health benefits of steam rooms, proper evidence not found.

Safety and Who Should Check First

• Heart conditions. A review lists unstable angina, recent heart attack and severe aortic stenosis as contraindications to sauna bathing. [6] See your clinician if you have heart disease, high or low blood pressure, or take blood pressure medicines. A literature review noted that blood pressure medicines may make blood pressure drop on standing after bathing. [1]
• Alcohol. Alcohol during sauna bathing increases the risk of low blood pressure, heart rhythm problems and sudden death and should be avoided. [6]
• Heat illness and fainting. The NHS lists being too hot, or not eating or drinking enough, as causes of fainting. [8] Leave and cool down if you feel dizzy, sick or unwell.
• Pregnancy. A 2001 review concluded sauna bathing was safe in uncomplicated pregnancies of healthy women, [6] while a review of hot tub use says overheating is the key concern in early pregnancy. [9] Ask your prenatal clinician before using a sauna.
• Reduced fertility in men. The sauna systematic review reported one small study (n = 10) in which sperm production was disrupted and recovered after stopping. [4]

This site does not give a universal temperature or time. Safe limits depend on the person, medicines and the facility. More in the safety guide.

Qualifications and Regulation

Saunas and steam rooms are normally run by gyms, spas and hotels, and operators do not generally need a health license. Inspection and hygiene rules vary by country and local authority. Ask the facility about cleaning schedules and how it handles medical emergencies.