Saunas are showing up everywhere lately, from gym recovery suites to infrared blankets marketed as longevity tools. The science behind them is more substantial than most wellness trends, but also more specific about what actually works. Here’s what researchers have found.
Can Sauna Use Actually Help You Live Longer?
The evidence is genuinely strong, though it comes with important caveats. The most cited research is a long-running Finnish cohort study, published in JAMA Internal Medicine in 2015, that tracked 2,315 men for over 20 years.
Men who used a sauna four to seven times per week had a 40 percent lower risk of dying from any cause and a 50 percent lower risk of fatal cardiovascular disease compared to those who went just once a week. The associations held after adjusting for smoking, alcohol, blood pressure, cholesterol and physical activity.
A 2018 follow-up in BMC Medicine brought women into the picture and found the same linear pattern: more sessions per week, lower cardiovascular mortality risk, with no ceiling on benefit.
The honest framing is “associated with,” not “causes,” since the data is observational. But the effect size is large and dose-dependent, which researchers consider a meaningful signal.
What About the Infrared Sauna at Your Gym?
Infrared saunas are popular, but they haven’t been studied for long-term longevity outcomes. All of the major cardiovascular and mortality data comes from traditional Finnish dry saunas running at 80 to 100 degrees Celsius (176 to 212 degrees Fahrenheit). Infrared models typically run at 49 to 65 degrees Celsius (120 to 150 degrees Fahrenheit), which is meaningfully cooler.
Infrared still raises core body temperature, elevates heart rate and triggers sweating, so there’s real physiological overlap. But whether that translates to the same long-term cardiovascular outcomes hasn’t been tested.
The Mayo Clinic’s current guidance, updated in September 2024, describes infrared sauna benefits as preliminary. If you’re using one for recovery or relaxation, that’s reasonable. If longevity data is the motivation, you’re extrapolating from traditional sauna research.
How Often and How Long Do Sauna Sessions Need to Be?
The Finnish studies point to specific thresholds. Four to seven sessions per week showed the strongest association with reduced mortality, but two to three sessions per week still produced a 27 percent lower cardiovascular mortality risk compared to once-weekly use. Session length matters too: sessions of 19 minutes or longer produced more protective effects than shorter ones in the data. The typical temperature in these studies was a minimum of 174 degrees Fahrenheit.
Hydrating before and after each session is considered essential. Skipping alcohol around sauna time is also consistently recommended across the research.
Can Sauna Use Protect Against Dementia?
The same Finnish cohort that produced the cardiovascular findings also turned up a notable cognitive result. A 2017 study in Age and Ageing found that men using the sauna four to seven times per week had a 66 percent lower risk of dementia and a 65 percent lower risk of Alzheimer’s disease compared to once-weekly users.
Researchers believe the connection runs through cardiovascular health: regular heat exposure improves blood vessel function and reduces arterial stiffness, which in turn supports healthy blood flow to the brain over time.
What Is the Sauna Actually Doing to Your Body?
Heat acts as a controlled stressor that triggers several useful adaptations. During a session, heart rate climbs to 100 to 150 beats per minute and plasma volume expands, conditioning the cardiovascular system in ways that overlap with moderate aerobic exercise.
Heat also activates heat shock proteins, particularly HSP70, which repair damaged proteins and reduce systemic inflammation. A 2025 review in the International Journal of Allied Health Sciences and Practice walks through these mechanisms in detail.
Over time, regular sauna use is linked to improved endothelial function, lower resting blood pressure and reduced arterial stiffness, which researchers point to as the likely bridge between heat exposure and both heart and brain outcomes.
Who Shouldn’t Use the Sauna?
Pregnancy, especially the first trimester, is a clear reason to avoid sauna use entirely. The same goes for unstable cardiovascular disease, recent stroke, active fever or infection and alcohol intoxication.
People taking diuretics, beta-blockers or any transdermal medication patches should check with a doctor first since heat increases drug absorption through the skin in ways that can shift dosing significantly. Children under 16 and anyone with uncontrolled high blood pressure should also approach sauna use cautiously and with medical guidance.
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