What is freezing (medical)
Freezing (congelatio) is a condition in which the medicine is any damage to the skin or other tissues due to extreme cold, because the tissue ice crystals arise that damage the cells.
However, at temperatures above are not low enough can even tissue damage that can not be called strictly freezing but for completeness here will be treated.
At -15 ° C or less begin to constrict blood vessels in the limbs and the skin. This allows the body loses less heat and vital body parts can remain on temperature. In extreme cold or when the body is exposed to cold this protection can, however, in the peripheral circulation causing a dangerously decreased blood flow. The combination of low temperature and poor circulation can destroy tissue. The risk of injury is greatest in the areas which are furthest from the heart, and with most of the surface area that is exposed to the cold. These body parts are especially the toes, fingers, ears and nose. The phenomenon is related to but not the same as hypothermia (general hypothermia, qv).
Risk factors for cold injuries include the use of beta-blockers and having diseases like diabetes or Raynaud's disease or Raynaud's phenomenon.
In actual freezing is intracellular water in the ice state over. This leads to ice crystals which damage the cell membrane so that the cells die. Of these, in the field of dermatology are sometimes also used by abnormalities dosed to freeze, for example, with liquid nitrogen. Real frostbite occurs mainly in people staying in freezing cold with strong winds, such as polar explorers and mountaineers. In these cases, ears, nose points, toes and fingers affected most often.
In World War I became cold injury much when soldiers hours with wet feet had to stand in the trenches without really freezing there was "trench foot" (trench foot).
There are also specific diseases where symptoms occur at a level of koudeblootsteling that is well tolerated by others or, for example, chilblains (pernio) or in the presence of cold agglutinins.
Symptoms
Generally will be freezing together with white skin and a burning or prickling sensation, and initially severe pain. If the cold continues the body is numb. As to the tissue, and in particular, the nerves and blood vessels, severe damage is inflicted will arise gangrene and amputation may be required. If the freeze remains untreated, the skin is dark gradually after a few hours. Skin affected by frostbite is completely black and looks loose and skinned like he was burned.
Prevention and Treatment
A number of factors may contribute to cold injuries such as extreme cold, wet clothes, high winds, and poor circulation. The latter can be caused by tight clothing or boots, cramped positions, fatigue, certain medications, smoking, alcohol or diseases that affect the blood vessels, such as diabetes.
If prevention is the good clothes can be worn cold resistant and the areas that cover most at risk. Mittens in cold weather (no gloves) are worn and wind resistant, water-resistant multi-layer clothing. A scarf and hat can help to prevent heat loss.
If someone has symptoms of frostbite he must be brought to a warm room. If medical help can come easily, the frozen body parts can be wrapped in clothes. Warm rub 'snow is nonsense, and dangerous. If it is unlikely that the hands after the defrosting can be kept warm throughout the treatment must be delayed for it to freeze can cause worse damage again. Otherwise the frozen parts must in warm (not hot) water be held until the feeling has returned. If anyone is suffering from hypothermia, it must be treated first.