SOME LIKE IT HOT
Can regular sauna sessions support a healthy heart? A look at the research
The Finnish tradition of sauna bathing dates back thousands of years. The wood-lined rooms are usually heated with a stove topped with stones.
Lounging on a towel in a cozy, dark room filled with hot air can feel relaxing and restorative. A sauna's high temperature — which usually ranges between about 150 F and 195 F — causes your blood vessels to dilate, which can raise your heart rate and increase blood flow throughout your body.
But does routine sauna use have any eff ect on your cardiovascular health?
"Population-based studies involving thousands of people suggest that those who take saunas regularly have lower rates of heart disease than people who don't take saunas," says Dr. Prashant Rao, a sports cardiologist at Harvard-affiliated Beth Israel Deaconess Medical Center. For more than a decade, though, researchers have been trying to tease out whether this is a cause-and-eff ect relationship, he adds.
How saunas affect your heart and circulation
A 2023 study in the Journal of Applied Physiology included 41 people (mostly men, with an average age of 62) with stable coronary artery disease. Researchers randomly assigned half of them to take Finnish saunas for 20 to 30 minutes four times a week, while the other half followed their regular lifestyle routines. After eight weeks, there were no meaningful diff erences between the two groups in their blood pressure values or other measures of vascular health, such as the flexibility and responsiveness of their arteries.
A review in the September 2025 issue of the American Journal of Preventive Cardiology analyzed findings from this study along with 19 other randomized controlled trials of passive heating interventions. These included saunas as well as hot-water bathing and hot yoga. Their conclusion: these practices don't improve most of the common measures of heart health, including cholesterol, inflammation or arterial stiff ness.
One possible exception was reduced blood pressure, with a drop of about 4 points in systolic blood pressure (the first number in a reading) in the combined studies. Among those at increased risk for cardiac disease, the drop was smaller (about 2.5 points). But even these small changes were not well supported, given the limitations and mixed findings of the diff erent studies.
So why do frequent sauna users seem to enjoy better heart health? Perhaps these relatively short, randomized trials simply didn't last long enough to capture the cardiac benefits, which may require years or even a lifetime of basking in a sauna, Rao says. Or, "it's possible that people who use saunas frequently are healthier in general and also belong to a higher-than-average socioeconomic group, which could explain their improved heart health," he says.
A sauna session can mimic the feeling you get after exercising. But use a sauna as an adjunct rather than a replacement for exercise, says Rao, who frequents the sauna at his gym after exercising.
Safety tips for using saunas
Because a sauna can temporarily lower your blood pressure, be cautious using them if you have low blood pressure or certain heart conditions, including valve disease (such as aortic stenosis) or heart failure.
Stay inside for just five minutes at first, paying close attention to any symptoms. Leave if you feel extremely hot, lightheaded or dizzy. It's also a good idea to cool down gradually; don't go straight outdoors in cold weather. Finally, be sure to hydrate afterward to replenish fluids lost from sweating.
Sauna variations
The Finnish tradition of sauna bathing dates back thousands of years. The woodlined rooms are usually heated with a stove topped with stones. The air is very hot (about 175 F) and dry, though sauna bathers periodically add water to the stones to produce a vapor known as lyly. On average, Finnish people take saunas two or three times a week for up to 20 minutes at a time.
■ Variations on this theme include dry saunas (in which no water is added to the heated rocks) as well as the opposite: a steam sauna (also called a steam bath or Turkish bath). These are typically built of tiles, glass or acrylic material. While the temperature is usually about 120 F, these sealed, extremely humid spaces feel much warmer.
■ Infrared saunas use infrared radiation, which heats your body directly rather than heating the air around it. Temperatures inside these rooms usually range from 120 F to 140 F.
