What is a magnesium jacuzzi? Ice baths, sauna and cold therapy explained

Magnesium jacuzzi

A warm jacuzzi dosed with magnesium chloride rather than plain water — the same mineral behind Epsom-salt baths, at a concentration that stays on the skin rather than needing to be absorbed through digestion. A soak typically runs around 30 minutes.

Magnesium absorbed this way is linked to muscle relaxation and, for many people, noticeably deeper sleep the same night. It is the gentlest of the three main stages, and the one to end a session on rather than start it — finish here, not start here, is the house rule.

Ice bath (cold immersion)

Full-body immersion in water held close to ice temperature, typically for two to three minutes at a time. The benefit is not proportional to how long you can stand it — two minutes done regularly, with slow controlled breathing, outperforms one heroic five-minute sit that leaves you gasping.

Used for recovery after exertion and, anecdotally and in some research, for a sharp lift in alertness and mood that lasts the rest of the morning. The house guidance is simple: breathe out slowly, and never hold your breath while submerged.

Sauna

Dry heat for 15 to 20 minutes, raising core temperature and heart rate in a way that mimics moderate cardiovascular exercise. Regular sauna use is associated with better circulation and, in some studies, cardiovascular benefit over time.

It is also, unglamorously, the fastest way on the property to stop thinking about your inbox. Long enough to sweat properly; not so long that fifteen minutes starts to feel heroic rather than restorative.

Red light therapy

The newest addition to the circuit, and Gili Air's first red light studio. Red and near-infrared wavelengths for skin, joints and post-sun recovery, taken for 12 to 20 minutes at a time. The protocol is deliberately undramatic: you sit still, and that is the whole session. It pairs well on the days you skip the ice bath, since red light is fine to use daily where cold immersion works better every other day.

Why the sequence matters

Heat first, then cold, then rest, repeated up to three rounds, then magnesium to finish — not the reverse, and not blended into one session without gaps between stages. Five minutes of rest in the shade between rounds is where most of the adaptation actually happens, so it is worth resisting the urge to rush straight back in. We run through the full structure, including a five-day plan built around it, in our wellness retreat guide.

Who should skip it

Cold immersion is not advisable with a cardiac condition, during pregnancy, or with uncontrolled blood pressure — speak to your doctor before you travel, and tell our therapists when you arrive so they can adjust the circuit rather than have you skip it 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.

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