How hot, how long, how often? It depends on what you want out of it. Heat is a dose, and the right dose shifts with the goal. Here are the three protocols worth knowing, the numbers behind them, and the safety rules that keep the sauna useful instead of dangerous. Most of these specifics line up with the Huberman Lab heat protocols.

The baseline

Traditional sauna research sits at 80-100°C (176-212°F), with sessions of 5 to 20 minutes. If you are new, start cooler and shorter, then build over weeks. Acclimating gradually beats forcing a “perfect” protocol on day one, and it is safer.

Protocol 1: heart and longevity

5 to 20 minutes, 2 to 3 times a week, up to 7. The Finnish data got its best numbers at the higher end of frequency, so if longevity is the goal, aim for regular over long.

Protocol 2: mood and stress

About 1 hour a week total, split across 2 to 3 sessions. This is the sweet spot for the endorphin lift and lower cortisol without overcooking it. For most people chasing the mental benefits, this is the one.

Protocol 3: growth hormone

Once a week or less. Four 30-minute sessions in a single day, with about 5 minutes of cooling between them, ideally semi-fasted (no food for 2 to 3 hours beforehand, since lower blood sugar helps the release). One study using aggressive repeated heat saw growth hormone climb up to 16-fold. Do not run this daily. The response fades fast with frequent heat, which is exactly why you save it.

Hydration is not optional

Aim for roughly 16 oz (about 500 ml) of water for every 10 minutes in the heat, and add electrolytes. You are sweating out more than water, and the dizzy, drained feeling people blame on the sauna is usually just dehydration.

Timing

An afternoon or early-evening session can help you sleep. Your core temperature drops in the hour afterward, and that dip is one of the cues your brain uses to feel sleepy.

Want to add cold?

Alternating sauna and a cold plunge is its own skill, with its own rules and one real trap. I cover it in Sauna and ice bath contrast therapy.

Safety, the part people skip

• Skip the sauna, or clear it with a doctor first, if you are pregnant, under 16, or have a heart condition, an arrhythmia, or low blood pressure.
• Never mix heat with alcohol. It is a genuinely dangerous combination for your blood pressure and your judgment.
• Trying to conceive? Repeated heat can lower sperm count for a while. It recovers in roughly 45 to 60 days after you stop, and cool packs during a session can soften the effect.
• Get out the moment you feel dizzy, nauseous, or lightheaded. When you are new, do not sauna alone.

My routine

Three or four sessions a week, 15 to 20 minutes at around 85°C, a bottle of water with electrolytes on the bench, usually late afternoon. Once a month or so I run the longer growth-hormone style day on an empty stomach. Nothing clever. The habit is the hard part, not the protocol.

New to the why? Start with Sauna Benefits. Buying a unit? Infrared vs. Traditional Sauna.