A 20-year Finnish study tracking about 2,300 men found frequent sauna use was associated with lower long-term risks of cardiovascular disease, hypertension, respiratory illness and Alzheimer’s, with the biggest gains among people using saunas 4-7 times a week.
Researchers said the strongest evidence supports traditional Finnish saunas, where heat raises core temperature by 1-2 degrees and boosts heart rate, blood flow and sweating; they cautioned against assuming steam rooms, hot baths and infrared saunas deliver identical effects.
Heat therapy also appears to aid athletic recovery by improving circulation and muscle repair, while claims that sweating “detoxifies” the body are weak because the liver and kidneys remove most pollutants.
Experts warned benefits have limits: sessions longer than 30 minutes, alcohol use, and exposure for pregnant people or those with heart conditions or low blood pressure can raise risks of fainting, cardiovascular strain or overheating above 40 degrees.
Cold plunges, often paired with saunas, have thinner evidence—some studies suggest short-term recovery or mood benefits, but results are mixed and safety concerns include potentially fatal cold-water shock.