Hypothermia, frostbite and chilblains – how to help – reviewed and updated November 2019

As the weather grows colder it is important to protect yourself from the dangers of the cold. The elderly, frail, ill and very young are most susceptible to extremes of temperatures, however, anyone can suffer from hypothermia and its effects can be extremely serious.


Hypothermia is defined as the point at which the core body temperature falls below 35°C. Bearing in mind the usual outside temperatures in the UK, and the huge surface area of our skin, it is easy to see how quickly we can lose body heat and could develop hypothermia.

Small children and babies are particularly at risk as their temperature control area in the brain is not fully developed. Elderly people are also at risk from hypothermia as metabolism slows as you get older. If people are out in cold conditions with insufficient warm clothing they can quickly develop mild hypothermia and in the case of an older person who has fallen outside, this can swiftly escalate to severe hypothermia and this is life-threatening.

Severe hypothermia can affect the clotting factors in the blood and so wounds are likely to bleed more and be harder to control. Severe hypothermia also affects the stability of the heart and so they are more likely to experience a cardiac arrest.

Exposure to cold water and wet clothing brings body temperature down rapidly and people with high levels of alcohol or drugs in their system find it harder to maintain their body temperature. Therefore, if someone has collapsed outside a pub during the festive season, hypothermia is a very real threat.


Signs and symptoms

  • Pale, quiet and cold to touch.
  • They may be shivery and then stiff with cold.
  • As hypothermia develops further, they become confused, disorientated and may lose consciousness – severe hypothermia kills.


  • Remove cold, wet clothing.
  • Put on warm dry clothing.
  • Cover their head as considerable heat is lost from here.
  • Wrap them up in coats and blankets, increase the room temperature if possible as well.
  • If you are unable to get indoors, wrap them in a foil blanket and use a survival bag and shelter if possible.
  • Give them small sips of warm (non-alcoholic) drinks.
  • Always seek medical advice. If their condition deteriorates phone the emergency services.


If they lose consciousness and are breathing put them in the recovery position.

If they stop breathing start CPR.

if they are very cold, avoid moving them if at all possible, as the extreme cold can cause abnormal heart rhythms and any swift movement could cause a cardiac arrest. If you do need to move them, to get them somewhere warmer, do this extremely carefully and phone an ambulance for additional advice and help.

Do not use hot water bottles or put the person in a bath to warm them. This concentrates on warming their extremities and can conversely dilate their blood vessels making it harder to warm their core. Hot water bottles can also cause burns.


Frostbite refers to the freezing of body tissue (usually skin) that results when the blood vessels contract, reducing blood flow and oxygen to the affected body parts. Frostbite is most likely to affect those parts of the body furthest away from the body core and, therefore, have less blood flow, including feet, toes, hands, fingers, nose, and ears. These body parts get so cold that ice crystals form in the cells and destroys them.

The casualty may develop pins and needles, tingling and then numbness in the affected area.

The skin becomes hard and changes first to white, then blue and finally turns black as the cells die.

As the area is warmed it can become hot, red and very painful.

Frostbite should always be assessed and treated by a health professional.



Carefully remove jewellery if possible – rings may need to be cut off.

Do not rub the injury as this will make things worse. To stop the freezing getting worse, cup the affected area in your hands. Do not start to warm them if there is a danger of the area re-freezing. Move them indoors and start to warm them slowly by placing the affected area in warm water. Refer for medical help as soon as possible.


Related conditions


Chilblains can occur as the result of dry cold. The cells do not freeze but the extremities become itchy, bluish-red in colour and swollen. If it is not treated the casualty may develop blisters. Treatment is the same as for frostbite.

Trench foot:

Trench foot is caused by prolonged exposure to wet and cold conditions. The cells do not freeze but symptoms are similar to frostbite.

We cover most common injuries and illnesses on our award-winning first aid courses. Book to join us now and ensure you have the skills to help in an emergency.

It is strongly advised that you complete an Online or attend a Practical First Aid course to understand what to do in a medical emergency. Please visit firstaidforlife.org.uk or call 0208 675 4036 for more information about our courses.

First Aid for life provides this information for guidance and it is not in any way a substitute for medical advice. First Aid for Life is not responsible or liable for any diagnosis made, or actions taken based on this information.

Emma Hammett
Author: Emma Hammett