Why the cold catches up with you afterwards

You climb out of a chilly lough or a February sea feeling surprisingly fine. That feeling is a bit of a trick. In cold water, your blood vessels narrow and pull blood away from your skin and limbs, keeping your core protected. The moment you get out and the air touches bare skin, those vessels begin to open again, sending cool blood from your arms and legs back towards the middle of your body. Your core temperature can carry on dropping for twenty to thirty minutes after you are dry and dressed — that is the notorious after-drop.

It is why the shivering often starts in the car park rather than the water, and why the period just after you exit deserves more planning than the swim itself. Everything you need should be waiting for you before your toes touch the water, not rummaged for with numb hands and blue fingers.

Lay your kit out before you get in

Think of it as a runway from the water to warmth. Set it up in the order you will need it, and keep it in a bag or a box so the wind does not scatter it while you swim. A changing mat or a piece of old carpet is a small luxury that saves your feet from frozen tarmac and gravel.

• A dry robe or a large changing towel — roomy enough to get changed underneath, ideally with a warm fleece lining.
• A woolly hat — a huge amount of heat escapes through a wet head, so this goes on early.
• Warm layers — thermal base layer, fleece, then a windproof outer layer. Two thin layers beat one thick one.
• Warm socks and boots — soft, easy-on shoes you can shove feet into without laces or buckles.
• Gloves or mittens and a neck buff.
• A flask of hot squash, tea or coffee, plus a snack.
• A towel for a quick pat-down — drying vigorously wastes time and heat.

If you swim with a group, agree who is watching the clock and who is keeping an eye on anyone new. Ten minutes in six-degree water is a long time for an inexperienced swimmer.

The first five minutes after you exit

Speed matters, but panic does not. Get out while you still feel comfortable and can speak clearly — that is your real exit signal, not the time on your watch. Walk briskly to your kit, get out of the wind if you can, and start with your feet.

Dry your feet first, pull on socks and hat, then step into your dry robe and peel the wet costume off underneath it. Towelling robes and changing towels exist precisely for this: you stay covered, keep some dignity and lose far less heat. Once the costume is off, work upwards — base layer, fleece, outer layer, gloves, boots.

A small trick worth adopting: loosen the lid of your flask before you swim. Cold hands cannot grip a stiff vacuum seal, and there is nothing more dispiriting than wrestling with a thermos while shivering.

Rewarm gently, not all at once

It is tempting to dive into a hot shower or a scalding bath. Resist it. Rapid, intense heat on chilled skin can send blood rushing to the surface, drop your core temperature further and leave you feeling faint or dizzy. Slow and steady is the way.

• Get dry, get dressed, get out of the wind — in that order.
• Sip a warm drink rather than gulping it. A flask of hot squash with a little sugar is ideal.
• Keep moving gently: a short walk back to the car generates heat from the inside.
• Add layers as you warm, and take them off if you start to sweat.
• Save the hot bath for later, once the shivering has settled and you feel properly warm again.

If you are still shivering hard after half an hour, or you feel confused, slur your words or cannot use your hands properly, that is not something to shrug off. Get somewhere warm, get help, and do not drive.

Flask, food and the little comforts

A flask earns its place in every swim bag. Fill it with something warm and slightly sweet — hot blackcurrant, ginger squash, tea with honey, or a mild broth if you prefer savoury. Caffeine is fine in moderation, but alcohol is not: it widens blood vessels and increases heat loss, so the post-swim pint can wait.

Pack a snack with carbohydrate and a bit of protein — a flapjack, a banana, a handful of nuts, a sandwich. Eating something within twenty minutes of getting out helps you warm up and stops the energy crash that often follows a cold swim. Keep a spare set of dry clothes in the car, too, just in case the first set gets damp in the rain.

Building it into a routine

The swimmers who enjoy winter best are the ones who have made the after-swim ritual automatic. Kit packed the night before. Flask filled and lid loosened. Robe, hat and socks on top of the bag. Someone else around, ideally, with a phone and a warm car nearby if needed.

Shorter swims, regular outings and a proper rewarming routine will do far more for your enjoyment than any amount of gritted teeth. Cold water is wonderful — it is the bit afterwards that decides whether you come back next weekend. Look after that bit, and the whole thing becomes a pleasure rather than an ordeal.