What does a sauna actually do?

What a session involves

Dry heat, typically 80–90°C, in a wood-lined room built to hold that temperature evenly rather than in hot spots. There’s no ritual to it beyond sitting still and letting your body do the work — no oils, no steam, nothing to apply. You sweat, your heart rate climbs, and fifteen minutes later you step out considerably more relaxed than you went in.

What it actually does

Heat raises your core temperature and heart rate in a way that mimics moderate cardiovascular exercise — your heart works harder to move blood toward your skin and cool you down, which over repeated sessions is linked to better circulation. Regular sauna use is associated in some studies with cardiovascular benefit over time, alongside the more immediate effect: it is, unglamorously, the fastest way on the property to stop thinking about your inbox.

None of this replaces exercise or medical treatment for a cardiovascular condition — it’s a complement, and the evidence for long-term benefit comes mostly from populations using saunas several times a week over years, not from a single holiday session.

How long, how often

Fifteen to twenty minutes is the house guidance — long enough to sweat properly, not so long that it stops feeling restorative and starts feeling like an endurance test. Most healthy adults can use a sauna daily without issue, provided you rehydrate properly afterward; the heat and sweating cost you more fluid than a session in the sun would.

Before or after exercise?

After, not before. Sauna raises your heart rate and mildly dehydrates you, which adds fatigue rather than warming you up for exertion. If you’re doing a morning swim or the island’s cycling loop, save the sauna for afterward — or for the evening, on its own.

Pairing it with cold immersion

Sauna is the first stage of Soma Vita’s full contrast circuit: heat first, then the ice bath, then rest, repeated up to three rounds, finishing in the magnesium jacuzzi. You don’t need the full sequence to get something from a sauna session on its own, but the order matters if you do the whole circuit — heat first is the one rule worth keeping.

Who should be careful

Sauna is not advisable during pregnancy, with a cardiac condition, or with uncontrolled blood pressure — speak to your doctor before you travel if any of those apply, and tell our therapists when you arrive so they can suggest an alternative rather than have you skip the circuit outright. The full longevity circuit is restricted to guests 18 and over, a stricter line than the hotel’s general 14+ policy; massage and the rituals menu remain open from 14.

Written by the team at The KOHO Air Hotel, a boutique wellness retreat five minutes’ walk from Gili Air harbour. We answer these questions by message most days — just ask.

Common questions