Cold plunge safety: how to start the right way

Cold water is safe for most healthy adults when you respect a few simple rules. Most of them are about the first minute and about building up gradually.

Check with your doctor first if…

• you have a heart condition or high blood pressure
• you are pregnant
• you have any other medical condition or take medication and are not sure cold water is right for you

Understand the first minute

Getting into cold water triggers the cold shock response: a gasp, fast breathing and a higher heart rate. It peaks in the first seconds and in most people settles within about a minute. Research by Professor Mike Tipton's group at the University of Portsmouth shows it gets smaller with practice, and the effect can last for months. Knowing it will pass is half the battle.

Seven rules for a safe session

1. Start warmer and shorter. 12–15°C for 2–3 minutes, then build up over a few weeks. See How cold should a cold plunge be?
2. Legs first, then down to the chest. Keep your head and face out of the water.
3. Breathe out slowly, never hold your breath. Long breath-holds and putting your face in cold water add strain to the heart.
4. Stay still. Moving makes the cold feel more intense.
5. Get out if you feel unwell, dizzy, confused or shiver uncontrollably. See How long should you stay in a cold plunge?
6. No alcohol before or after a session.
7. Warm up naturally afterwards. Dry off, get dressed and move around. Our How to Plunge guide covers the routine.

Electrical and setup safety

• Connect the chiller to a standard socket on a circuit with a residual-current device (RCD), as European regulations require.
• Outdoors, use a weather-protected socket and avoid long extension cables.
• Keep the chiller ventilated and the floor around the tub dry; an insulating floor mat helps.
• Keep the lid on between sessions, and supervise children around the water.

Frequently asked questions

Should I plunge alone?

For your first sessions, have someone nearby. Once you know how your body reacts, plunging alone at home is common, but keep your phone within reach.

Is cold water safe in pregnancy?

Talk to your doctor or midwife before you start.

Sources

• Tipton M, Mekjavic I, Eglin C. Permanence of the habituation of the initial responses to cold-water immersion in humans. European Journal of Applied Physiology, 2000.
• Eglin CM et al. Rapid habituation of the cold shock response. Extreme Physiology & Medicine, 2015.