Frostbite is a tissue injury caused by cold. In addition to the cold as the culprit, the humid environment, and poor local blood circulation in the body are also accomplices. When cold acts on local skin and other tissues, it causes vasoconstriction and tissue ischemia. Ice crystals are formed between cells, and the cells are deformed or necrotic. After leaving the cold environment, the tissue gradually reheat, vasodilation, increased exudation, the formation of edema and even blisters, resulting in frostbite. The lower the cold temperature and the longer the exposure, the more severe the frostbite. Frostbite occurs at the end and exposed parts of the body, such as hands, feet, ears, nose, cheeks, etc. Depending on the severity of frostbite, there are often four degrees of frostbite. In the first degree, the skin only shows edematous erythema, in the second degree, blisters or blisters appear on top of the erythema, in the third degree, blue or black necrosis of the skin appears, and in the fourth degree, frostbite of the subcutaneous muscles and even bones occurs. Most frostbite can be prevented. In a cold environment, attention should be paid to protection against cold and warmth, such as wearing gloves, masks, hats, ear muffs, etc., and clothing and shoes should be of appropriate size and loose-fitting. Also pay attention to prevent humidity and keep the skin dry. In addition to reduce the time spent in the cold environment, if you need to stay to appropriate exercise to promote blood circulation. First and second degree frostbite should be promptly rewarmed, keep the local tissue clean and dry, and apply frostbite cream topically as appropriate. Larger blisters should be aspirated for herpetic axils. Generally will recover well, there will be some hyperpigmentation in the short term. Third or fourth degree frostbite must be treated in hospital. The main treatment is local necrotic tissue debridement and the application of drugs to improve blood circulation in the frozen area. Severe cases may require skin grafting or amputation. Therefore, the prevention of frostbite is very important.