Understanding exposure to high and low temperatures

What is hypothermia?

Hypothermia is a condition that occurs when someone’s body temperature drops below 35°C (95°F). Normal body temperature is around 37°C (98. 6°F). Hypothermia can become life-threatening quickly, so it’s important to treat someone with hypothermia straight away.

Signs and symptoms

Look for:

Shivering, cold and pale with dry skin .

Unusually tired, confused and have irrational behaviour.

Reduced level of response.

Slow and shallow breathing.

What to do

Treating hypothermia outdoors

1. If the casualty is outside, try to get them indoors. If you are unable to get them indoors, try to take them to a sheltered place as quickly as possible, shielding the casualty from the wind.

2. Remove and replace any wet clothing and make sure their head is covered.

Do not give them your clothes - it is important for you to stay warm yourself.

3. Try to protect the casualty from the ground. Lay them on a thick layer of dry, insulating material such as pine branches, heather, or bracken. If possible put them in a dry sleeping bag and/or cover them with blankets. If available, wrap them in a foil survival blanket. You can use your body to shelter them and keep them warm.

4. Call 999 or 112 for emergency help.

Do not leave the casualty alone. Somebody must be with them at all times. If you are in a remote area and cannot call for emergency help, send two people to get help together.

5. If the casualty is fully alert, offer them warm drinks and high energy food such as chocolate.

6. Monitor their breathing, level of response and temperature while waiting for help to arrive.

Treating hypothermia indoors

1. If you are indoors, cover the casualty with layers of blankets and warm the room to about 25°C (77°F).

Do not place any direct heat such as hot water bottles or fires near a casualty as they may cause burns.

2. Give them something warm to drink, like soup, and/or high-energy food, like chocolate.

Do not give the casualty alcohol in an attempt to warm them, it will make hypothermia worse.

3. Seek medical advice. Hypothermia could be disguising a more serious illness such as a stroke, heart attack or an under-active thyroid gland.

4. Monitor their breathing, level of response and temperature until they recover.

Never give a casualty alcohol.

Never place direct sources of heat on or near the casualty.

Never warm babies or elderly too quickly (e.g by placing them in a bath).

What is heatstroke?

Heatstroke is caused by a failure of the ‘thermostat’ in the brain which regulates the body’s temperature. This means the body is unable to cool down when it becomes too hot.

It could be caused by spending too much time in the sun, having a high fever, or from taking non-prescription drugs such as Ecstasy. It can also occur after heat exhaustion when sweating ceases.

Your priority is to cool them down as quickly as possible and get them to hospital.

Signs and symptoms

Look for:

Headache, dizziness and discomfort . 

Restlessness and confused.   

Hot, flushed and dry skin.

Less responsive quickly.  

Pulse full and bounding.   

Body temperature above 40°C (104°F).

What to do

1. Quickly move the casualty to a cool place and remove as much of their outer clothing as you can. Call 999 or 112 for emergency help.

2. Help them to sit down in a comfortable, supported position. Wrap them in a cool, wet sheet and keep pouring cold water over the sheet until their temperature falls to at least 37.5°C (measured under the armpit).

If a sheet is not available, fan them or sponge them down with cold water.

3. Once their temperature has come down to normal, replace the wet sheet with a dry one.

4. While waiting for help to arrive, monitor their level of response and temperature.

If their temperature starts to increase cool them down again using the same method.

If they become unresponsive at any point, open their airway, check their breathing and prepare to give CPR.