The short version
Heat stresses your body on purpose. Your heart rate climbs, blood vessels open, and circulation moves the way it does during moderate exercise.
Then you get out, and your body works to come back down. That recovery is where most of the benefit lives.
Not the sweating. The coming back down.
How long should you stay in
New to it
Five to ten minutes. Get out before you want to. Come back tomorrow.
Used to it
Fifteen to twenty minutes at 175–195°F. Most research clusters here.
How often
The frequency data is stronger than the duration data. Three to four sessions a week shows more in the research than one long weekly session.
Get out if you feel dizzy, nauseous, or stop sweating. Those are not signs of toughness. They are signs to leave.
Who should be careful
- Pregnancy — ask your doctor first, every time.
- Heart conditions or blood pressure medication.
- After drinking. Alcohol and heat is the combination that sends people to the emergency room.
- Anyone who is already dehydrated.
Common questions
What are the benefits of a sauna?
Best supported: cardiovascular conditioning, muscle recovery, stress reduction, and sleep quality when used earlier in the day. Weakly supported: detox and fat loss. You are losing water weight, and it comes back with your next glass.
How long should you stay in a sauna?
Fifteen to twenty minutes once you are used to it. Five to ten when you are starting. Duration matters less than going regularly.
Is the sauna good when you have a cold?
A mild head cold with no fever, and you feel up to it — fine. Running a fever — no. You are already heat-stressed and adding more is the wrong direction.
What should you wear?
In a public sauna, a towel, or loose cotton. Skip synthetics, which trap heat against skin. Never wear anything you exercised in.
Traditional, infrared, or steam?
Traditional runs hottest and has the most research behind it. Infrared runs cooler and reaches deeper, which many people find more tolerable. Steam sits at 100% humidity and feels hotter than the thermometer says. Best one is the one you will actually use.
Before or after a workout?
After, for recovery. Before, and you arrive at your workout already heat-stressed and short on fluid.