Hypothermia
Hypothermia occurs when a person’s normal body temperature of around 37°C (98.6°F) drops below 35°C (95°F).
It is usually caused by being in a cold environment. It can be triggered by a combination of things, including prolonged exposure to cold (such as staying outdoors in cold conditions or in a poorly heated room for a long time), rain, wind, sweat, inactivity or being in cold water.
Signs and symptoms
The symptoms of hypothermia depend on how cold the environment is and how long your casualty is exposed for.
Severe hypothermia needs urgent medical treatment in hospital. Shivering is a good guide to how severe the condition is. If the person can stop shivering on their own, the hypothermia is mild, but if they cannot stop shivering, it is moderate to severe.
MILD CASES
In mild cases, symptoms include:
- Violent, uncontrollable shivering
- Being unable to think or pay attention
- Confusion (some people don’t realise they are affected)
- Loss of judgement and reasoning
- Difficulty moving around or stumbling (weakness)
- Feeling afraid
- Memory loss
- Fumbling hands and loss of coordination
- Drowsiness
- Slurred speech
- Listlessness and indifferent
- Slow, shallow breathing and a weak pulse
MODERATE CASES
The symptoms of moderate hypothermia include:
- Violent, uncontrollable shivering
- Being unable to think or pay attention
- Confusion (some people don’t realise they are affected)
- Loss of judgement and reasoning
- Difficulty moving around or stumbling (weakness)
- Feeling afraid
- Memory loss
- Fumbling hands and loss of coordination
- Drowsiness
- Slurred speech
- Listlessness and indifferent
- Slow, shallow breathing and a weak pulse
SEVERE CASES
The symptoms of severe hypothermia include:
• Loss of control of hands, feet, and limbs
• Uncontrollable shivering that suddenly stops
• Unresponsiveness
• Shallow or no breathing
• Weak, irregular or no pulse
• Stiff muscles
• Dilated pupils
TREATING HYPOTHERMIA
As hypothermia can be a life-threatening condition, seek medical attention as soon as possible.
Hypothermia is treated by preventing further heat being lost and by gently warming the casualty.
If you are treating someone with mild hypothermia at home, or waiting for medical treatment to arrive, follow the advice below to prevent further loss of heat.
- Move the casualty indoors, or somewhere warm, as soon as possible
- Once sheltered, gently remove any wet clothing and dry them
- Wrap them in blankets, towels, coats (whatever you have), protecting the head and torso first
- Increase activity if possible, but not to the point where sweating occurs, as that cools the skin down again
- If possible, give them warm drinks (but not alcohol) or high energy foods, such as chocolate, to help warm them up
- Once their body temperature has increased, keep them warm and dry
It is important to handle anyone that has hypothermia very gently and carefully.
Things you should NOT do:
- Do not warm up an elderly person using a bath, as this may send cold blood from the body’s surfaces to the heart or brain too suddenly, causing a stroke or heart attack
- Do not apply direct heat to the arms and legs, as this forces cold blood back to the major organs, making the condition worse
- Do not give them alcohol to drink, as this will decrease the body’s ability to retain heat
- Do not rub or massage their skin, as this can cause the blood vessels to widen and decrease the body’s ability to retain heat. In severe cases of hypothermia there is also a risk of heart attack
When to seek medical help
If someone you know has been exposed to the cold and they’re distressed or confused, and they have slow, shallow breathing or they’re unresponsive, they may have severe hypothermia. Their skin may look healthy but feel cold. Babies may also be limp, unusually quiet and refuse to feed.
Cases of severe hypothermia require urgent medical treatment in hospital. You should call 999 to request an ambulance if you suspect that someone you know has severe hypothermia. Do not give them any food or drink.
As the body temperature drops, shivering will stop completely. The heart rate will slow and your casualty will gradually lose responsiveness. Be prepared to resuscitate if they stop breathing normally.