Frostbite is where the skin and underlying tissues become damaged when in cold tempertaures. Anyone who spends a lot of time in cold weather condtions is at risk.
When the skin and underlying tissues freeze because of an exposure to low temperatures, this is when frostbite occurs. You are at risk of frostbite of you spend a lot of time outside in cold weather conditions.
Any part of the body can be affected by frostbite but the hands, feet, ears, nose and lips are more likely to be affected.
Types of Frostbite
How severe frostbite is and how fast it develops, depends on how cold the conditions are and how long you have been exposed.
The two types of frostbite are:
Superficial – with this type of frostbite, only the skin and top level of tissue become affected. You are likely to recovery fully when the skin and tissue has thawed.
Deep – damage from frostbite is more likely to be permanent if the deeper tissue is frozen and blood vessels become affected.
Amputation may be necessary if gangrene (dead tissue) occurs.
Symptoms of Superficial Frostbite
Pins and needles and a throbbing or aching is felt in the affected area during the early stages of frostbite. The skin becomes cold, white and numb. You might feel a tingling sensation as well. This stage of frostbite is common in people who work or live in cold climates and is also called “frostnip.” Most commonly affected body parts are fingers, nose and ears and toes.
Prolonged exposure to cold temperatures, after the early signs, causes more damage to the tissues and the area which is affected feels hard and frozen. The skin turns red and blister when you are out of the cold and the tissue has thawed out. You also might feel itching and swelling.
This frostbite affects the top layers of skin and tissue. This is why it is known as superficial frostbite. The skin under the blisters is usually not affected but medical treatment is still required to ensure that there is no lasting damage.
Symptoms of Deep Frostbite
Frostbite becomes more severe when exposure to the cold carries on. The skin is white, blue or blotchy and tissue under is hard and cold when touched. The tendons, muscles, nerves and bones may have further damage.
Vital medical attention is needed for deep frostbite.
Blood filled blisters form as the skin thaws and they turn into thick black scabs. It is likely that some of the tissue has died at this stage. This called gangrene and might require amputation to stop infection.
Causes of Frostbite
Exposure to low temperature is what causes frostbite. How severe it is depends on how cold the temperature is and how long exposure lasts for.
The following are factors which decrease temperature and increase the rate that your body loses heat. These can all have an impact on frostbite developing:
severe weather conditions, e.g. blizzards
a wind chill
suitability of clothing and if your clothing is wet.
Your body’s response to extreme cold is what causes the damage to the skin and tissue.
As blood vessels narrow, blood flow to the extremities, e.g. hands, feet, ears, lips and nose slows down. Blood flow to the body’s vital organs is increased to keep the body alive. The extremities get colder as blood is redirected away from them. Fluid in the tissue becomes frozen and ice crystals form which can break cells and damage tissue.
Further damage can be caused by prolonged exposure to the cold. The blood vessels widen to try and maintain the function of the affected areas as the temperature carries on dropping. However, the returning blood leaks out of the blood vessels because the cells have been damaged by ice crystals and this causes further damage to the tissue.
Treatment for Frostbite
Your priority should always be to take necessary precautions to prevent frostbite.
You should seek medical attention straightaway if you do get frostbite. There are some steps that you can take to treat frostbite if medical assistance is unavailable:
move to a warmer place if you can
stop further hear loss by replacing wet clothing with soft dry clothing
wrap the body in blankets to warm it and protect the frostbitten areas
do not apply direct heat, e.g. fire or heater or rub the affected area.
The areas affected by frostbite need to be re-warmed. You should only begin this process once you are out of the cold because if you do not and the frozen parts are re-exposed to cold temperatures, this can cause further damage that is irreversible. Re-warming a part of the body that is frostbitten should ideally be done under medical supervision and can be painful.
Slowly warm the affected area by immersing it in warm (not hot) water. Water of 40-42 degrees celcius is recommended. Warm wet-packs can be used if a tub of water is not available. Re-warming should take around 20-40 minutes. Colour and sensation should start to return as the affected area starts to warm gradually.
Wrap the frostbitten area in clean bandages, with the fingers and toes separated out, after it has been thawed. Avoid infection by keeping the skin clean. Avoid too much movement and elevate the limbs if you can. Any pain can be eased with painkillers.
The skin will be discoloured, blister and eventually scab over after re-warming. New pink skin forms under the discoloured skin and scabs if the frostbite is superficial and the area normally recovers within six months.
The tissue might die and gangrene may develop if the frostbite is more severe. Gangrene will turn the affected area black or blue. This damage is permanent and the area either falls off or will have to be amputated.
Amputation of frostbitten areas is usually not done until three to four weeks after the initial injury to allow for the full extent of damage. This means that no healthy tissue is removed unnecessarily. If the dead tissue is life-threatening, surgery can be done before this time.
Permanent problems can be left after frostbit for some people, e.g. pain, numbness and stiffness.
Prevention of Frostbite
If you spend any time exposed to the extreme cold (below freezing), it is very important that you take measures to make sure that your skin is protected. Frostbit happens very quickly in temperatures below freezing.
What your wear is very important if you are going to spend time in cold temperatures. Ensure that your hands, feet, nose, ears and lips are protected well because these are the most vulnerable and are usually the first to be affected. It is important to wear a warm hat, gloves, well-insulated boots and thick well-fitting socks.
It is more effective to wear a number of thin layers as opposed to a few thick ones. Thin layers are able to trap air which warms to the body’s temperatures and acts as extra insulation. Each layer should be larger than the one below to stop local pressure and constriction and they should all fit well.
You are more vulnerable to frostbite if you have a medical condition that causes blood vessel damage or circulation problems or if you smoke or take drugs that restrict your blood vessels.