What should you know before trying cold-water swimming?

Cold-water swimming has gone from eccentric winter habit to something whole groups of friends do before work, red-faced and delighted. The appeal is real: the sharpness of it, the hot drink afterwards, the camaraderie of people in woolly hats on a shingle beach in February. The cold is also real, and the safety bodies are clear that it deserves respect. Here is what to understand before the first dip. None of it makes cold water safe on its own, and local rules, lifeguards and conditions always come first.

Cold water shock

The Royal Society for the Prevention of Accidents describes cold water shock as a physical response to rapid entry into water at 15°C or lower. It can make you lose control of your breathing: gasping, and breathing much faster than normal. RoSPA notes it can happen to anyone, however fit, and in any open water. Check the water temperature where you plan to swim; many venues and local groups post it.

Practically, that shapes everything about how you get in:

• Never jump or dive in. Walk in gradually.
• Pause at waist depth. Splash your face, neck and arms. Wait until your breathing calms before you start swimming.
• Breathe out slowly. Many swimmers find long, slow exhales help them settle before they set off.

If the cold or anything else catches you out, RoSPA's Float to Live advice is to tilt your head back with your ears in the water, relax, breathe, and use your hands to help you stay afloat until the effects pass, then call for help or move to safety.

Short is the whole point

Your first cold swims should be dips, measured in minutes, not lengths. Get out while you still feel good. The Royal Life Saving Society UK warns regular cold-water swimmers not to rely on how they feel to judge how long to stay in, and advises keeping winter swims short. Treat shivering, clumsy hands or a slowing stroke as your cue to head for the exit.

Never alone, and pick your place

Both RoSPA's open water swimming guidance and RLSS UK advise against swimming alone. Better still, start at a lifeguarded beach or a supervised open-water venue, or join a local group of cold-water swimmers who know the spot.

• Know your exit before you get in, and check that it is easy to climb out when your hands are cold.
• Swim parallel to the shore, where RoSPA notes the water is likely to be shallower.
• Check conditions: weather, wind, tides and currents. If it looks rough, it is a coffee day.
• Be seen: a bright cap and a tow float, ideally one with a whistle, as RoSPA suggests.

Wetsuit or skin

There is no rule that cold-water swimming has to be done in a swimsuit. RLSS UK says a wetsuit is generally safer in water of 18°C or below and does not recommend beginners swim in water under 12°C at all. Neoprene gloves, socks and a hat make a striking difference to comfort. Our page on whether you need a wetsuit goes deeper.

Getting warm afterwards

This part surprises people. The Outdoor Swimming Society explains afterdrop: your core can keep cooling after you leave the water, so you are likely to feel colder some minutes later than at the moment you got out. Its advice:

• Get wet layers off and dry yourself straight away.
• Layer up quickly: thermals, jumper, warm jacket, hat, gloves, something to stand on while you change.
• Sip a warm drink and get somewhere warm.
• Do not drive while you are still shivering.

Pack your kit in the order you will need it, so the hat and dry top are on top. Our wild swim kit list has the full bag.