Hot weather itchy skin can be caused by physiological reasons, but also by summer dermatitis and other allergic dermatitis and other pathological reasons. 1. Physiological reasons: if only itchy skin, no other dermatological symptoms, may be due to excessive sweat caused by physiological itching, diligent bathing, keep the skin clean and moisturized. 2. Pathologic causes (1) Summer dermatitis: refers to the inflammatory skin disease triggered by high environmental temperature and humidity, sweat and dust on the skin stimulation, manifested as symmetrical erythema or papules on the limbs and trunk, accompanied by intense itching. It is necessary to get out of the hot environment as soon as possible to ensure that the skin is dry and clean, keep ventilation, with 3% boric acid solution and anti-itching agents (such as glycerite lotion, prednisone ointment, etc.) for treatment. (2) Other allergic dermatitis: If you have allergic dermatitis (e.g. eczema, urticaria, etc.), it will stimulate the nerve endings to cause an itchy sensation when the temperature is too high or the ultraviolet radiation is too much. This can be treated by taking medications such as loratadine and cetirizine to address the cause. If there is a hot weather skin itchy situation, exclude the physiological causes of the basis, need to go to the hospital in time to identify the specific cause of the disease after targeted treatment.