Frostbite is a common type of skin injury, caused by exposure to frost. Very cold temperatures cause tissues to freeze, starting at skin level. It usually affects the extremities, where blood circulations is weaker, typically the feet and especially the fingers and toes. Frostbites have several levels of severity. Mild frostbite can be treated and causes no permanent damage. However, when the deep tissues are affected, the damage can become permanent and recovery is impossible. In severe cases, parts of fingers or toes completely fall off. Obviously, the easiest way to prevent frostbite is to avoid exposure to cold, or to be prepared with adequate clothes for protection.
Depending on the depth of the frozen tissues, frostbite has several degrees of severity. These degrees are very similar to the ones used in the classification of burns. Human skin consists of two major layers, the top one is named the epidermis and the inner one is the dermis. Fatty tissues are located under the dermis and then muscles, tendons and other similar structures can be found.
The 1 degree frostbite is also known as a frostnip. The initial exposure to cold cause the skin to turn either pale or red and you can actually feel the low temperature. In time, the skin becomes numb or somehow itchy. Frostnip is not a severe condition and the skin fully recovers from it. While warming back up, tingling and moderate pain is possible.
The next degree, the 2 degree frostbite, is also known as a superficial one. As the exposure to cold continues, the skin initially turns red before losing its color and becoming white. The water inside the tissue freezes, forming ice crystals. Sometimes the skin feels warm, which is a dangerous and misleading sign. Warming the skin back up will give it a very strange color, possibly purple or blue. Since there is damage to the tissues, warming up can be painful, with redness and inflammation. A blister full of fluid can appear on the skin the next day.
Finally, the deep frostbite consists of the degrees 3 and 4. In such cases, the entire skin is frozen and the tissues under it start to freeze as well. Since the nerves in the area are no longer functional, the sensation of cold usually goes away and there is no pain at all. Muscles and articulations start to fail and warming back always results in large blisters. The frozen tissues do not recover and become black.
The numbness makes frostbite dangerous because it is sometimes hard to notice unless others spot it. This typically happens on the nose, fingers, toes, chin, ears or cheeks.
The initial symptom of frostbite is of course the feeling of cold on the exposed part of the skin, normally a finger or toe. The next signs are numbness or a sensation of burning. Warming the frozen area back up causes various symptoms, from burning to pain or a sensation that resembles electrocution.
Frostnip, or the first and least severe degree of frostbite, makes the skin red or shite in color, as well as insensitive. Sometimes, the skin becomes hard to touch. The damage can be healed completely, often even without treatment.
The second degree of frostbite makes the skin become stiff, with a hard texture. Its color becomes red or blue, with significant swelling. The skin gets covered in blisters full of fluid, which can either be clear or opaque, resembling milk.
The next degree, the third, can also cause blisters but these are red since the liquid inside is blood. The skin is hard, with a white or blue color. After several weeks, thick black areas emerge, which are actually dead tissues.
The most severe form of frostbite is the fourth degree. The damage is no longer limited to the skin, the tissues below it being affected as well. The skin will become red, then turn black as the tissues die. Muscles and joints freeze, sometimes even the bones.
Frostbite can have many different looks. These depend of several factors, for example the extent of the frozen area and the degree of the condition.
Depending on the degree, frostbite can be treated with simple first aid measures or more complex forms of treatment. Frostnip is the only degree where first aid is enough, all of the other forms need special treatment and the intervention of a doctor.
There are a number of simple advices in case of frostbite. The most obvious advice is to stay warm and avoid cold temperatures for some time, as well as strong winds. Avoid walking if your feet are frozen and don't rub frostbitten areas or heat them too suddenly. The blisters that emerge on the skin are actually a natural form of protection and should not be removed. The blisters will break themselves once the damage is healed.
After rewarming a frostnip, you can use a calming lotion or a product based on aloe vera to calm down the affected area. This can be repeated multiple times per day. Mild frostbites can also be treated using the anti-inflammatory drug ibuprofen, which is cheap and widely available over the counter, under various commercial brands. If the frostbite was severe and your doctor prescribed antibiotics or strong painkillers, make sure you take all of the pills in time.