Red bumps on the body are especially itchy in hot weather, considering that it may be prickly heat, cholinergic urticaria, solar dermatitis and so on. It can be treated by lowering the room temperature, reducing sweating, avoiding sun exposure, and taking oral antihistamines and topical medications if necessary. 1. Prickly heat: Prickly heat is caused by long time being in hot and humid environment and blockage of small sweat glands in the ducts. If the symptoms are mild, stay away from the hot environment and the skin can disappear by itself when it cools down, and if it is a little bit heavy, you can apply glycerite lotion, keep the room cool and ventilated, and the local skin is fresh and clean. 2. Cholinergic urticaria: cholinergic urticaria is a limited edema of the skin and mucous membranes, is caused by exercise, stress or passive body temperature rise caused by the skin local center of the body temperature rise, prompting the release of acetylcholine caused by the physician’s guidance of oral antihistamines, such as loratadine, etc., and can be used topically with glycerine lotion. 3. solar dermatitis: solar dermatitis and ultraviolet radiation, should be away from the sun’s environment, daily life attention to sunscreen, the local can be used externally basic moisturizer, the symptoms of the more serious can be used externally hydrocortisone and other hormonal ointment. Hot weather body red bumps, you should go to the hospital, clear cause after standardized treatment, and follow the doctor’s instructions for medication.