By Fuentes, founder of Lanoviss — 23 September 2026. About the author.
Most healthy adults do well with 10–15 minutes per round in a Finnish sauna at 80–90 °C, followed by a cool-down about as long as the round, repeated two or three times. First-timers should start at 5–8 minutes. The hotter or more humid the room, the shorter the round: 5–10 minutes above 90 °C, while a cooler infrared cabin allows 15–30 minutes.
Those numbers are a starting point, not a target. Below is a round-length table by room type, the research on why heat and humidity change your limit, what the long-term data says about session length, and the signs that mean you should get out now.
How long should you stay in a sauna, by temperature?
Use the table as a rule of thumb. We built it from the studies and guidance cited in this article; it is not a medical limit, and your own signals always override it.
| Room | Typical air temperature | Round length, regular users | Round length, first visits |
|---|---|---|---|
| Finnish sauna, mild | 70–80 °C | 12–20 min | 8–10 min |
| Finnish sauna, classic | 80–90 °C | 10–15 min | 5–8 min |
| Finnish sauna, hot | 90–100 °C+ | 5–10 min | 3–5 min |
| Banya or heavy löyly (hot and very humid) | Hot, with frequent steam | 5–10 min | 3–5 min |
| Steam room | 40–50 °C at 100% humidity | 10–15 min | 5–10 min |
| Infrared cabin | 35–60 °C | 15–30 min | 10–15 min |
For reference: the Finnish Sauna Society recommends 80–100 °C, though many people are happy at 70 °C (thisisFINLAND). Harvia puts the ideal steam room at 45–50 °C (Harvia). Infrared research protocols have used 35–50 °C for 30 minutes and 50 °C for 10 minutes. The differences between room types are covered in Sauna vs Banya vs Steam Room vs Infrared.
Why do hotter or more humid saunas mean shorter rounds?
Because both heat and humidity make your heart and cooling system work harder, and they do it independently. In a 2026 University of Jyväskylä study, 50 healthy adults completed four 10-minute sauna sessions under different conditions. Average heart rate rose from 79 to 121 beats per minute and core temperature from 37.4 to 37.8 °C — and both climbed further as either temperature or humidity went up.
Humidity matters because your body cools by evaporating sweat. In moist air, sweat stays on the skin instead of evaporating, so the heat keeps building. That is why a round with lots of löyly, or a banya, feels much hotter than the thermometer suggests and should be shorter.
Where you sit matters almost as much as the thermostat. Air at face height on the top bench can run 80–100 °C while the floor sits near 30 °C (our head-height breakdown). Moving down one bench is the easiest way to stretch a round without changing anyone else's sauna.
How long should a beginner stay in a sauna?
Start with 5–8 minutes on a lower bench, cool down, and stop after one or two rounds. Your body adapts to heat with practice: in a controlled German study, regular sauna users showed a training effect in heart rate, sweat and skin blood flow compared with non-users.
A simple progression for a sauna at 80–90 °C:
- Week 1: two rounds of 5–8 minutes, lower bench.
- Week 2: two rounds of 8–10 minutes; try the middle bench.
- Week 3: two or three rounds of 10–12 minutes.
- Week 4 onwards: 10–15 minutes per round, wherever feels good.
The Finnish view on endurance contests is blunt: competing to see who can stand the most heat is "both silly and unhealthy" (thisisFINLAND). Leaving early is normal. Our first-time etiquette guide covers what else to expect.
Is staying longer in the sauna better?
Not necessarily. The best-known data comes from the Kuopio study, which followed 2,315 Finnish men aged 42–60 for a median of almost 21 years. Compared with sessions under 11 minutes, sessions of 11–19 minutes were linked to a 7% lower risk of sudden cardiac death, and sessions over 19 minutes to a 52% lower risk. Session length was not linked to lower all-cause mortality.
That is an observational association in middle-aged men from eastern Finland in the 1980s, not proof that minutes cause the benefit. The journal's own editor noted that nobody knows why the frequent bathers lived longer — the heat, the relaxation or the lifestyle that allows for it. The study also recorded time per session, not whether that time was one round or several. It is not a reason to sit through 20 unbroken minutes.
How many rounds should you do, and how long should you cool down?
Two or three rounds is typical; most Finns have at least two sessions in the hot room (thisisFINLAND). Cool down for roughly as long as you were in, with a shower, fresh air or a swim, and drink water between rounds.
Finish by letting your body temperature return to normal before you dress, until you have stopped sweating. People with heart complaints or high blood pressure should avoid swimming in cold water straight after the hot room, according to the same Finnish guidance. If you are coming from the gym, the timing rules in Sauna After a Workout apply too.
How long should you stay in an infrared sauna or steam room?
Longer in infrared, shorter in steam. Infrared cabins heat the air far less, so 15–30 minutes is common; research protocols have used 10 minutes at 50 °C and 30 minutes at 35–50 °C.
A steam room runs only 40–50 °C, but at 100% humidity sweat cannot evaporate at all, so 10–15 minutes is enough for most people. Treat both with the same rule as a Finnish sauna: leave when it stops feeling good.
What are the signs you should get out of the sauna now?
Get out at the first sign of dizziness, headache, nausea, weakness or feeling faint. The CDC lists these, along with heavy sweating and muscle cramps, as warning signs of heat exhaustion (CDC). Sit or lie down somewhere cool, drink water, and don't go back in that day.
Never combine the sauna with alcohol. A Finnish forensic study found that half of the people who died in saunas between 1990 and 2002 had been drinking. Sauna deaths are rare — fewer than 2 per 100,000 people a year in Finland — and a review in The American Journal of Medicine ties alcohol during sauna bathing to low blood pressure, arrhythmia and sudden death.
Does a sauna hat let you stay in longer?
It can delay the scalp and ear discomfort that ends many rounds, but no controlled study has measured it, and it does not change your heart rate or core temperature (what is and isn't known about sauna hats).
The reasoning is simple. Your head sits in the hottest air in the room, and the tops of your ears have almost no insulation. A felt hat puts a layer of wool between that air and your scalp, so the part of you that usually complains first complains later. That extra comfort is not a reason to ignore the warning signs above. The Lanoviss merino wool sauna hat is 3 mm of seamless pressed merino felt, one size for 55–61 cm heads, for $59.99 CAD.
Frequently asked questions
How long should you stay in a sauna the first time?
5–8 minutes on a lower bench, then cool down. One or two rounds is enough for a first visit. Add a couple of minutes per round each week as your body adapts.
Is 20 minutes in a sauna too long?
For one unbroken round in a Finnish sauna at 80–90 °C, 20 minutes is longer than most people need. Two rounds of 10 minutes with a cool-down between is easier on your body and gives you similar total time. In a cooler infrared cabin, 20 minutes is normal.
Is 30 minutes in a sauna too long?
In a traditional sauna, yes for a single round for most people; split it into two or three rounds. Infrared studies have used 30-minute sessions at 35–50 °C, so 30 minutes can be reasonable there.
How long should you stay in a sauna at 90 °C?
About 5–10 minutes per round, less if the air is humid or you are new. Heart rate and core temperature rise faster as temperature and humidity go up.
How long should you cool down between sauna rounds?
Roughly as long as the round itself: 10–15 minutes with a shower, fresh air or a swim, plus water. Go back in once your breathing and heart rate feel normal.
How long should you stay in a steam room?
10–15 minutes for most people. Steam rooms run only 40–50 °C, but at 100% humidity sweat cannot evaporate, so the heat builds quickly.
How many times a week should you use a sauna?
In the Kuopio study, men who used a sauna 4–7 times a week had lower cardiovascular risk than once-a-week users, but that is an association, not proof. Any frequency you enjoy and recover from is fine for healthy adults.
Sources
- Laatikainen-Raussi I, et al. "Temperature and humidity independently influence thermoregulatory responses during Finnish sauna bathing." Temperature, 2026. DOI · University of Jyväskylä release
- Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. "Association between sauna bathing and fatal cardiovascular and all-cause mortality events." JAMA Internal Medicine, 2015;175(4):542–548. JAMA · summary
- Kowatzki D, et al. "Effect of regular sauna on epidermal barrier function and stratum corneum water-holding capacity in vivo in humans: a controlled study." Dermatology, 2008. Karger
- "Bare facts of the sauna in Finland." thisisFINLAND (Finnish Ministry for Foreign Affairs). finland.fi
- Harvia. "How to build a steam room?" harvia.com
- Mero A, et al. "Effects of far-infrared sauna bathing on recovery from strength and endurance training sessions in men." SpringerPlus, 2015. PMC
- Ahokas EK, et al. "Effects of repeated use of post-exercise infrared sauna on neuromuscular performance and muscle hypertrophy," 2025. PubMed
- Kenttämies A, Karkola K. "Death in sauna." Journal of Forensic Sciences, 2008. PubMed
- Hannuksela ML, Ellahham S. "Benefits and risks of sauna bathing." The American Journal of Medicine, 2001. amjmed.com
- CDC. "About heat and your health." cdc.gov
This article summarises published research and common practice for general information. It is not medical advice. If you have a heart condition, high or low blood pressure, or are pregnant, ask your doctor before using a sauna.