What is frostbite?
Frostbite is an injury that can affect any part of your body exposed to freezing temperatures. Temperatures below 0 °C can cause damage to your skin and the tissues beneath.
What causes frostbite?
Your heart constantly pumps blood around your body via your blood vessels. The blood delivers oxygen which is vital for the survival and function of your tissues and organs.
In cold temperatures, your blood vessels become narrowed. This helps make sure that vital organs, like the brain, receive more blood. It also diverts blood flow away from your extremities, like your fingers and toes. This deprives them of the oxygen they need.
The cold temperature can also cause ice crystals to form in the tissue and cause damage.
If the ice crystals are left and the blood flow is not restored, then the tissue can die.
What are symptoms of frostbite?
The symptoms depend on the level of cold exposure and how advanced it has developed.
Early symptoms of frostbite include:
Numb skin or a tingling pins and needles sensation
Paler-looking skin colour
Aching or throbbing pain
In the intermediate stage of frostbite, the surface of the skin is damaged but the underlying tissue is still healthy. You might experience symptoms such as:
Purple-looking or blistered skin after the area has warmed
In more advanced stages of frostbite, you might experience:
The formation of black areas of thickened skin or scabs where tissue has died
The affected areas might be hard and cold to touch
If you’re worried that you or someone you know has symptoms of frostbite, move to a warmer environment and seek medical help.
If you’re experiencing constant shivering or breathing really quickly (hyperventilating), call 999 or go to A&E immediately.
Who is most likely to get frostbite?
Frostbite is more likely in people:
Who spend long hours working in cold environments, such as rescue workers and military personnel
Who are at the extremes of age
With pre-existing conditions such as Raynaud’s phenomenon or diabetes
Who smoke cigarettes
Who take medications which cause blood vessels to narrow, such as beta blockers
Who are homeless
Who take part in winter sports like skiing or mountaineering
What parts of the body does frostbite commonly affect?
Frostbite affects areas which are further away from the heart. Common areas affected include:
Fingers and toes
Hands and feet
How is frostbite diagnosed?
This is usually a clinical diagnosis made by an examination. Your doctor will listen to what happened and will be able to assess the area that is affected.
How is frostbite treated?
If you suspect you may have frostbite, follow these steps.
Move to a warm place as soon as you can. This will help stop the frostbite from getting worse and also prevent other problems like hypothermia.
If your clothes are wet or cold, take them off and replace them with dry, warm clothes if possible. Take off any shoes or jewellery covering the area.
Get medical attention as soon as possible. A healthcare professional will try to warm up the area with warm water around 37 degrees C. It’s important that the water is warm but not hot. This can be painful, so taking pain medicine should help.
If you’re worried that the area will be exposed to the cold again, don’t soak it in water. It could add to the damage once it’s reexposed to the cold.
In severe cases, you might need to be admitted to hospital as there is a risk of major damage and specialist treatment might be required.
How can I prevent frostbite?
Avoiding cold temperatures and dressing for the weather is usually enough to prevent frostbite. Remember to wear loose-fitting layers, thick socks and waterproof or padded boots. Mittens tend to be better than gloves as your fingers collectively share warmth.
It’s also important to remember the early signs of frostbite so you can catch it early, like the tingling pins and needles feeling.
When should I speak to a doctor?
If you have been exposed to cold temperatures and notice symptoms of frostbite, seek medical advice at the first instance, either by calling 111, a GP or 999, depending on how severe your symptoms are.
- Reviewed by:
- Dr Bryony Henderson, Lead GP at Livi