Recognising Early Signs of Hypothermia on the Fells

Why the fells can chill you faster than you expect

Hypothermia is not reserved for blizzard conditions on Ben Nevis. It begins when your core temperature drops below 35°C, and that can happen on a damp, windy day in the Peak District just as easily as in deep winter. The fell walking combination is brutal: wind strips heat from exposed skin, rain soaks clothing, sweat dampens baselayers, and fatigue slows your pace. Add a long lunch stop on a summit, or a wrong turn that delays you, and the body starts to lose heat faster than it can generate it. Wild campers are especially vulnerable at camp, when they stop moving and stand around in damp kit while pitching a tent. The key is to catch the shift early, before the casualty stops shivering and becomes properly unwell.

The early behavioural signs: quietness, grumbles and clumsiness

The first signs are often changes in personality and coordination rather than dramatic shivering. A chatty walking partner goes unusually quiet. Someone who is normally decisive becomes vague or grumbly. They may fumble with a zipper, drop a glove, or stumble on ground they would normally cross easily. Speech can become slurred, slow, or muddled. They might insist they are "fine" while clearly not fine.

• Stumbles: tripping on easy ground, losing balance, or walking into rocks.
• Mumbles: slurred, slow, or muddled speech that does not match the person.
• Fumbles: struggling with zips, buckles, map cases, or glove liners.
• Grumbles: unusual irritability, withdrawal, or flat refusal to carry on.

Treat any of these as a red flag, especially if they appear alongside cold hands, pale skin, or a reluctance to keep moving. Do not wait for severe shivering or confusion.

Physical clues and the shivering question

In mild hypothermia, shivering is a good sign: the body is still trying to warm itself. You may see cold, pale skin, blue lips, and a person hunched against the wind. They might complain of cold hands and feet, or need the toilet more often. As hypothermia worsens, shivering can become violent and uncontrollable, then stop altogether. That stopping is dangerous, not reassuring. Other signs include drowsiness, slow breathing, and a lack of interest in food or drink. On the fells, the wind chill can make 5°C feel like -5°C, so always assess the person, not just the thermometer. If they are shivering and coherent, you have time to act, but not much.

What to do immediately: warm, fuel, shelter, descend

Once you spot the signs, stop walking and deal with it. Get the casualty out of the wind and rain, and insulate them from the ground with a sit mat, rucksack, or spare foam mat. Add layers: dry baselayers if possible, then fleece, insulated jacket, waterproof shell, hat, gloves, and a buff. Wrap them in a survival bag or bivvy bag if you have one. Share warm, sweet drinks: flask tea, hot squash, or hot chocolate. Avoid alcohol and large amounts of caffeine. Give sugary snacks like flapjack, boiled sweets, or chocolate. If they can walk and are only mildly affected, keep them moving at an easy pace, but do not let them overexert and sweat. If they cannot walk, or their condition is worsening, shelter them properly and prepare to call for help. The golden rule is simple: descend without delay. Getting lower, out of the wind, and closer to warmth is the most effective treatment.

Descending safely and calling for help

If the casualty is mild and mobile, head downhill by the easiest safe route, not the most direct. Keep them in the middle of the group, with someone watching them constantly. Stop frequently to check speech, coordination, and shivering. If they become confused, drowsy, or stop shivering, treat it as an emergency. Call 999 and ask for mountain rescue. Give a clear grid reference, the number of people in your group, the casualty's condition, and any changes. Keep them horizontal and insulated, and share body heat if you have a sleeping bag or bothy bag. Do not give food or drink if they are drowsy or unable to swallow. Do not rub limbs or put them in a hot bath. Warm the core gradually, not the extremities.

Prevention for fell walkers and wild campers

Prevention is mostly about layers, fuel, and escape plans. Start with a wicking baselayer, add a fleece or synthetic midlayer, and carry a waterproof shell with taped seams. Pack a spare dry baselayer and socks in a dry bag. Eat little and often, and drink before you feel thirsty. Carry a flask of hot drink and high-energy snacks. For wild camping, pitch before you are exhausted, change out of damp clothes, and get into a dry sleeping bag with a suitable temperature rating. Use a sleeping mat with a good R-value; the cold ground will drain heat faster than the air. Know the forecast, including wind chill and rain, and have a lower-level escape route. Tell someone your plan and expected return time. On the fells, the weather can turn in twenty minutes, so check in with your group regularly. If someone goes quiet, ask them directly: "Are you warm enough?" Then act. A short, early descent beats a long, cold epic every time.