The gym sauna sits behind its little glass door, occupied by people who clearly know the rules — and the rules are posted nowhere. First-timers hover, unsure about towels, time and talk. Here is the unwritten protocol, written, plus the survival math that keeps sessions pleasant.

The Towel Protocols

One towel to sit on, always — bare skin on shared benches is the cardinal violation everywhere on earth. Swimwear rules vary by facility (gym saunas: usually worn); the sit-towel rule never does. A second small towel for the face marks you as a professional.

The Time Math

First sessions: 8-12 minutes, lower bench (heat rises — the top bench is the advanced seating). Exit at ‘pleasantly cooked’, never at dizzy. Veterans do rounds with cool-down breaks; first-timers do one round and a victory shower. Nobody is timing you but you.

The Hydration Ledger

A sauna session sweats out serious fluid — water before, water after, skip it entirely if you arrive dehydrated or post-happy-hour (alcohol plus sauna is a genuinely bad combination, not a spa tradition). The post-sauna water bottle is part of the ritual.

The Social Register

Sauna culture is quiet-friendly: low voices or comfortable silence, no phones (heat kills them anyway — poetic), nods over introductions. And the exit move: cool shower, slow rehydration, and that specific boneless calm that explains why entire nations organize their week around this.

Sit-towel always, ten minutes low bench, water on both ends, voices low. The glass door was never guarding experts — just people who learned these four rules one awkward visit before you.