Frostbite is a recurrent localized erythema and swelling caused by cold injury. Cold stimulation causes localized small blood vessel constriction in the skin, which results in tissue hypoxia, ischemia and cellular damage over time, followed by tissue edema and inflammatory reactions. People with poor peripheral blood circulation and long-term exposure to wet and cold environments are prone to frostbite. Frostbite is a common disease in winter, and once it occurs, it is often difficult to heal quickly during the cold season and will only gradually heal after the weather warms up. I. Characteristics of frostbite 1. It occurs in cold winters and can be aggravated by humidity. It is common in children, women, the elderly and those with poor peripheral blood circulation. 2. Characteristics of skin lesions. Swollen purplish-red spots with reduced skin temperature and discoloration under pressure, easily forming blisters, erosions and ulcers. Self-conscious itching or painful sensation. 3.Distribution. Preferably on the ends of the limbs and exposed parts, such as hands, feet, ears, face, etc. 4.Easy to recur. 5. Special types of frostbite: cold seborrhea – if you wear tight pants or jeans in the cold winter, erythema, nodules, and even ulcers and oozing will appear on the outer thighs. Prevention points 1, cold winter should pay attention to warmth, cold, wet. 2, strengthen nutrition, proper exercise, improve peripheral circulation. 3, quit smoking, try not to smoke. 4. Try to wear loose warm clothes. Reminder: Take effective warmth and cold-proofing and moisture-proofing measures after getting frostbite, and do not directly soak in hot water to avoid further aggravation of cold damage. Severe cases should go to the hospital for treatment in a timely manner.