Frostbite occurs in the fall and winter, and the most common sites are the ends of extremities such as the hands, feet and ears, and exposed areas. The typical presentation is localized swelling, erythema to purplish patches, with some nodules palpable under the skin, and a feeling of pruritus or swelling, especially after heat stimulation. There are four main points in the diagnosis of frostbite: 1. cold environment; 2. exposed areas or limb ends; 3. swollen or purplish patches; 4. itching or swelling sensation, aggravated by heat. Based on the above, it is not difficult to diagnose, mainly and allergic dermatitis (can have erythema with itching, but can occur throughout the year and anywhere on the body) or erythema multiforme (mostly caused by infections or medications and not as characteristic of frostbite). There are three key points in the treatment of frostbite: 1. Do a good job of preventing cold and keeping warm: for example, wear scarves, ear muffs, thick-soled shoes, etc., and clothing and shoes slightly larger, so that the air layer can play a role in insulating and keeping warm. 2, medication: external use of frostbite ointment to promote blood circulation, capsaicin ointment can be used to help massage when using medication, on the one hand, to promote absorption, on the one hand, to promote blood circulation. Oral medications such as dipyridamole, etc. 3, auxiliary care: active exercise, more warm food, such as lamb black tea, etc., more local massage, reduce hot and cold stimulation, especially do not use hot water to stimulate the affected area, which can easily aggravate the condition. Early detection and treatment, and mastering the correct method of protection are the keys to frostbite diagnosis and treatment.