How do I prevent hypothermia while hiking?
Layer and manage moisture
Hypothermia happens when your core temperature drops below 95°F (35°C). The biggest risk factor is wet clothing, whether from rain, sweat, or falling into water. Start with a moisture-wicking base layer (not cotton), add an insulating midlayer like fleece or down, and top with a waterproof-breathable shell. Adjust layers before you start sweating heavily—once you're wet, it's hard to dry out on the trail.
Pay attention to your hands, feet, and head, which lose heat fastest. Gloves, a warm hat, and extra socks can make a big difference. If you're hiking in cold, wet conditions, bring a dry set of clothes in a waterproof stuff sack.
- Avoid cotton; it holds moisture and loses insulation when wet.
- Use a base layer, insulating midlayer, and waterproof shell.
- Ventilate by opening pit zips or removing layers before you sweat.
- Pack spare gloves, hat, and socks in a dry bag.
- Change out of wet clothes as soon as you stop moving.
Fuel, hydration, and early action
Your body generates heat by burning calories, so eat high-energy snacks regularly even if you don't feel hungry. Drink water, but don't overdo it—too much water without electrolytes can lead to hyponatremia, which mimics hypothermia. Warm, sugary drinks like cocoa or tea can help if you have a stove.
Watch for the 'umbles'—stumbling, mumbling, fumbling, and grumbling—which are early signs of hypothermia. If you or a companion start shivering uncontrollably or seem confused, stop immediately. Get out of the wind and rain, add dry layers, and share a sleeping bag or emergency blanket if needed. If symptoms don't improve, evacuate.
Common mistakes
- Thinking hypothermia only happens in extreme cold—it can occur at temperatures as high as 50°F (10°C) if you're wet and windy.
- Ignoring shivering as just 'being cold'—uncontrollable shivering is a serious warning sign.
- Wearing cotton next to your skin, which stays wet and accelerates heat loss.
