Why the First Ten Minutes Matter Most

There is a particular kind of elation that comes with stepping out of a cold tarn on a breezy Cumbrian afternoon: heart pounding, skin glowing, the whole body buzzing. It is easy to stand about grinning and discussing the water temperature while the wind does its work. Try not to. The minutes straight after you exit are the ones that decide whether you spend the rest of the day feeling wonderful or shivering in the passenger seat with the heater on full.

When you are in cold water, blood is pulled away from your skin and limbs to protect your core. Once you climb out, those vessels open up again and chilled blood from your arms and legs travels back to the centre of your body. This is the afterdrop, and it means your core temperature can keep falling for twenty to thirty minutes after you are dry and dressed. The aim is not to warm up dramatically, but to stop losing heat and then let your body claw its way back steadily.

Strip Off and Dry Off — Quickly

The single most useful thing you can do is get out of wet clothing and into something dry. Wet fabric against the skin conducts heat away from your body many times faster than still air does, so every extra minute spent in damp swimwear is heat lost for nothing.

• Stand on a foam sit mat or folded jacket rather than cold rock, so you are not chilled through the feet.
• Turn your back to the wind before you start undressing — find a boulder, a wall or a bank of heather to shelter behind.
• Dry briskly with a large microfibre towel, paying attention to the head, armpits and groin, where heat loss is greatest.
• Pull on a dry base layer immediately. If you are changing under a robe or towel, do the top half first, then the legs.

If you have walked in wearing a wet top, get that off too. Warm, damp walking clothes are nearly as bad as nothing at all once the wind picks up.

Layer Up in the Right Order

Wind is the real thief on the fells. A still, damp day feels far kinder than a bright one with a stiff breeze coming off the tops, so your clothing needs to block moving air before it does anything else.

• Base layer: a dry synthetic or merino top and leggings. Cotton stays wet and should be left at home.
• Mid layer: a fleece or light synthetic jacket, which traps the warmth your body is producing.
• Outer layer: a windproof shell, worn from the moment you are dry, even if it is not raining.
• Extremities: a hat, dry gloves and dry socks, plus boots or trainers that have been kept out of the water.

A spare hat lives permanently in my rucksack for exactly this reason. It is astonishing how much difference a dry fleece beanie makes when your hair is still wet.

Warm From the Inside: Drink, Eat and Move

A flask of sweet tea is the classic fell-walking remedy and it works. Sip it slowly rather than gulping it down; a steady trickle of warm liquid helps you feel warmer and tops up the energy you have burned shivering. Something with sugar in it — tea with a spoon of honey, hot squash, or even just a handful of jelly babies — is ideal.

Skip the hip flask. Alcohol widens the blood vessels near the skin, which makes you feel flushed while actually speeding up heat loss, and it dulls the judgement you need to walk off the hill safely. Heavy coffee is best saved for the café at the end.

Eat something too. Flapjack, oatcakes, a piece of chocolate or a sandwich all give your body fuel to burn. Then start walking gently. A slow, steady plod to lower ground warms you far better than standing around, but resist the temptation to charge off at speed before your legs have woken up.

Keeping an Eye on Each Other

Cold water swimming on the fells is a sociable business, and that is part of what keeps it safe. Never swim alone, and never assume the quiet one in the group is fine. Mild shivering, pale fingers and a bit of clumsiness are normal and expected; they usually ease within half an hour of being dry, fed and moving.

Seek help if the shivering becomes violent and uncontrollable, or, more worryingly, stops altogether while the person is still cold. Confusion, slurred speech, fumbling with zips and a sudden apathy are signs of hypothermia. Get the person out of the wind, wrap them in everything dry you have, including a sleeping bag or emergency shelter, and call for help if they are not improving. Warm them slowly and gently — no hot baths, no vigorous rubbing of cold limbs and no forcing them to walk.

What to Keep in the Rucksack

• Large microfibre towel and a spare dry base layer, bagged separately from everything wet.
• A windproof shell and a warm hat, packed where you can reach them without unpacking the whole bag.
• A flask of hot, sweet tea and a high-energy snack.
• A foam sit mat, a dry bag for wet kit and a small emergency shelter.

Cold water is a joy, and the fells are a finer place to enjoy it than most. Get dry, get dressed, get warm from the inside out, and the glow will stay with you all the way back to the car.