Sauna Session Planner
Plan sauna session length by temperature for dry Finnish, steam, and infrared saunas.
Includes heart rate guidance and beginner versus advanced time limits.
Sauna use reduces cardiovascular mortality risk, improves heat shock protein production, and raises growth hormone. The dose is measured in temperature, duration, and frequency.
Types of sauna
Finnish dry sauna operates at 80-100C (176-212F) with 10-20% relative humidity. This is the most studied type. Most cardiovascular and mortality-reduction research comes from Finnish sauna populations using 80-90C for 15-20 minutes, 4-7 times per week.
Steam rooms operate at 40-60C (104-140F) but near 100% humidity. Sweat does not evaporate in steam, so the body heats faster for a given air temperature. The perception of heat is much stronger.
Infrared saunas operate at 45-65C (113-149F) and heat tissue directly rather than heating the air. Despite lower air temperatures, core temperature rises similarly to traditional saunas over longer sessions (30-45 minutes).
Session duration guidelines
The practical limit is when your heart rate exceeds 150 bpm or you feel dizzy, nauseous, or lightheaded. Most healthy adults reach this limit at 15-25 minutes in a 90C Finnish sauna.
A conservative approach: start at 80C for 8-10 minutes, exit, cool for 5-10 minutes, repeat 1-2 rounds. Total heat exposure per session: 15-30 minutes.
Hydration. Sweat rate in a 90C sauna is roughly 500-1000 mL per hour. Drink 400-600 mL of water before and replace after. Sports drinks are not necessary unless you are doing multiple long sessions.