Hypothermia Signs Outdoors

Hypothermia is a dangerous drop in body temperature below 35°C, and its early signs - shivering, tiredness, confusion and pale, cold skin - can be caught before a serious accident develops. If you think someone has it, the NHS says to call 999 and start warming them gently straight away.

Signs of hypothermia

Normal body temperature is around 37°C. The NHS lists these symptoms of hypothermia:

• shivering
• pale, cold and dry skin, with lips or skin that may turn blue or grey
• slurred speech
• slow breathing
• tiredness or confusion

Mountain Rescue England and Wales adds disorientation and loss of circulation in the hands or toes to the warning signs to watch for on the hill, and notes that children and older people are especially susceptible. On a walk these subtle warnings often show up first as a companion lagging behind, stumbling, fumbling with zips or straps, or making odd decisions. As hypothermia deepens the person may stop shivering altogether: that is a sign of worsening, not recovery, and it may be followed by drowsiness, a weak pulse, difficulty breathing and loss of consciousness.

Immediate action outdoors

Hypothermia is far easier to reverse early, so the most effective response in the open is to act on the first signs. Call 999 or 112: on the hills ask for the Police and then Mountain Rescue, and on the coast or in the water ask for the Coastguard. While you wait for help, follow the NHS steps, adapted to where you are:

1. Move the person indoors or somewhere sheltered as quickly as possible, out of the wind and rain.
2. Remove any wet clothing and replace it with dry layers if you have them.
3. Wrap them in a blanket, sleeping bag or dry clothing, covering the head, and put a mat, rucksack or anything dry underneath them to stop the cold ground drawing away heat.
4. If they are fully awake and able to swallow, give them a warm non-alcoholic drink and some sugary food like chocolate.
5. Keep them awake by talking to them until help arrives.

There are also things the NHS says not to do. Don't use a hot bath, hot water bottle or heat lamp to warm them up; don't rub their arms, legs, feet or hands; and don't give them alcohol to drink. Handle the person gently, and warm them gradually rather than quickly.

Cold water and immersion

Hypothermia risk isn't just about air temperature: wind, rain and wet clothing drain heat far faster than cold, dry air, and water is the fastest of all. The RNLI treats any water below 15°C as cold water, and a sudden fall in can trigger cold water shock, with uncontrollable gasping and rapid breathing. Those initial effects pass in less than a minute, so the RNLI's advice is not to try to swim straight away but to relax and float on your back until your breathing is under control.

Hypothermia in the water comes later: in UK coastal waters it usually takes more than 30 minutes of immersion before body temperature falls below 35°C, and then the person becomes exhausted and uncoordinated and may eventually become unresponsive. Anyone pulled from cold water, even if they seem well, should be kept warm and checked by the emergency services, and the same care applies to a walker or paddler who has been soaked and chilled for hours.