Environmental
Hypothermia
Warm a cold person gradually with dry clothing, blankets and warm drinks if alert; for severe cold or unresponsiveness, call 999 and warm them gently.
When to call 999. Call 999 if the person is very cold, drowsy, confused, slurring, shivering that has stopped despite the cold, or unresponsive. Severe hypothermia is life-threatening and needs emergency care; handle the person gently.
What to do
- Move the person somewhere warm and sheltered, out of wind and cold.
- Remove any wet clothing and replace it with dry layers, and cover them with blankets, including the head, leaving the face clear.
- If they are alert and can swallow, give warm (not hot) sweet drinks.
- Warm them gradually — do not use direct intense heat such as a hot bath, hot water bottle placed directly on skin, or a fire close to the skin.
- Keep them still and handle them gently, as sudden movement can be dangerous when very cold.
- If they are unresponsive and not breathing normally, call 999 and start CPR, continuing until help arrives.
Avoid
What not to do
Do not rewarm someone too quickly with hot baths, hot water bottles on bare skin or rubbing the limbs, and do not give alcohol — these can be dangerous. Do not assume someone is beyond help because they seem lifeless when very cold; continue CPR and call 999.
Afterwards and while you wait
Continue gentle rewarming and monitor the person until help arrives or they are clearly recovering. Anyone with more than mild hypothermia, or who was unresponsive, needs medical assessment. Prevent it by wearing warm, dry, layered clothing and avoiding prolonged cold and wet.
Education and reference only. This is general first-aid information aligned with UK guidance, not a substitute for a hands-on first-aid course or professional emergency care. In a life-threatening emergency, call 999 straight away.
Answers
Hypothermia: frequently asked questions
Why not warm a very cold person quickly?
Rapid rewarming, such as a hot bath, can cause a dangerous drop in blood pressure and heart rhythm problems. Gradual warming with dry layers, blankets and warm drinks is safer.
Is it worth doing CPR on someone who is very cold?
Yes. People who are severely hypothermic can sometimes be revived even when they appear lifeless, so continue CPR and call 999 — the saying is "not dead until warm and dead".
Related
Other environmental first aid
Sources
Where this is drawn from
- NHS — first aid
- St John Ambulance / British Red Cross first-aid guidance
- Resuscitation Council UK (where relevant)
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