Hypothermia: symptoms, causes and what to do in an emergency

The NHS lists the symptoms below. The British Red Cross adds that the person will be somewhere cold, and may be shivering, pale and cold to touch, confused, breathing more slowly and have a temperature below 35 degrees Celsius.

The NHS notes that on black or brown skin the colour change may be easier to see on the palms of the hands or the soles of the feet. Many instances of hypothermia happen indoors when it is cold and there is a lack of heating, so it is not only a risk for people outdoors.

• Shivering.

• Pale, cold and dry skin; skin and lips may turn blue or grey.

• Slurred speech.

• Slow breathing.

• Tiredness or confusion.

• In a baby: cold to touch, floppy, unusually quiet and sleepy, and may refuse to feed.

Hypothermia means the body is losing heat faster than it can make it. The NHS puts the threshold at a body temperature below 35C. The British Red Cross explains that the person's circulation of blood around the body, particularly to the skin, is reduced, which is why the skin feels cold to touch.

It is different from frostbite, which is freezing of the skin. The NHS says frostbite happens when the skin is exposed to temperatures of 0C or below, most often affects the fingers, toes, nose and ears, and is treated in hospital. A person with frostbite who is shivering a lot or struggling to stay awake may also have hypothermia.

If you think someone has hypothermia, the NHS and the British Red Cross both say to get medical help (call 999) and, while you wait, to warm the person gently. The Red Cross adds that if you have no blanket you could use extra clothing, sheets or towels, and that outdoors you could use items such as bin bags, newspaper or cardboard to protect against the cold ground.

• Move the person indoors or somewhere sheltered as quickly as possible.

• Remove any wet clothing and wrap them in a blanket, sleeping bag or dry towel, making sure their head is covered.

• If they are fully awake, give a warm non-alcoholic drink and some sugary food such as chocolate.

• Keep them awake by talking to them until help arrives.

• Make sure you or someone else stays with them.

• Do not use a hot bath, hot water bottle or heat lamp to warm them.

• Do not rub their arms, legs, feet or hands.

• Do not give them alcohol.

The NHS says people with hypothermia are usually treated in hospital. Your heart rate will be monitored and you may be given oxygen to help you breathe. You may also be given warm fluids straight into a vein to help your body warm up. Treatment in intensive care may be needed if you have severe hypothermia.

The NHS asks you not to drive to A&E. Ask someone to drive you or call 999 and ask for an ambulance, and bring any medicines you take.

The NHS says hypothermia happens when you get too cold and your body temperature drops below 35C. You can get it if you do not wear enough clothes in cold weather, stay out in the cold too long, fall into cold water, have wet clothes and get cold, or live in a cold house.

The NHS says people more vulnerable to the effects of cold weather include those aged 65 and older, babies and children under 5, people on a low income who cannot afford heating, people with a long-term health condition or a disability, pregnant women and people with a mental health condition.

The NHS winter health advice is to heat your home to a temperature that is comfortable, and if you can, to at least 18C in the rooms you regularly use, such as the living room and bedroom, particularly if you have a health condition. It also suggests looking in on vulnerable neighbours and relatives.

If you are concerned that an older relative or neighbour may have hypothermia, the NHS says to go to 111.nhs.uk or call 111. If they are seriously unwell, call 999.

For being outdoors in very cold conditions, the NHS frostbite advice is to wear several loose layers with a waterproof outer, a hat and scarf, gloves or mittens and thick socks and boots, and to eat and drink regularly if you are in the cold for long periods.

Hypothermia is an emergency, so the route the NHS gives is 999 or A&E rather than a booked appointment, whether you would otherwise use NHS or private care.

After recovering, people at risk of cold exposure, such as older people who live alone, may benefit from a review with their GP surgery about heating, medicines and general health. The NHS winter health page points to grants, benefits and advice that can help make a home more energy efficient, improve heating or help with bills.