Cold Plunges: What to Know Before You Try One

Cold plunges, ice baths and cold showers are hugely popular online. Many people say they feel more alert and refreshed afterwards. But cold water also carries real risks, so it's worth starting carefully.

What people report

• Feeling energised and alert
• A mood lift afterwards
• A sense of achievement

Research is still developing, and many claims online go beyond the evidence.

The risks

• Cold shock: sudden cold can cause gasping and a rapid rise in heart rate and blood pressure.
• Hypothermia with longer exposure.
• Drowning risk in open water.

How to start safely

1. Begin with a cold finish to a warm shower for 15–30 seconds.
2. Breathe slowly and steadily.
3. Build up gradually over weeks.
4. Keep sessions short.
5. Warm up afterwards with dry clothes and a warm drink.

Open water

Never swim in cold open water alone. Join an organised group, know your limits and get out if you feel very cold or unwell.