Most of the body itching when it is hot is due to the presence of skin diseases such as pruritus, prickly heat, cholinergic urticaria, etc., which should be promptly consulted to find out the cause of the disease. 1. Pruritus: Sudden change of temperature such as too hot bedding, sudden heat, etc. can cause the onset of pruritus, mainly manifested as generalized or localized itching, but the itchy skin does not have any obvious rash, the patient often feels itchy, scratching the skin can appear scratches, scabs, and even cause skin infections. 2. Prickly heat: It is a superficial, inflammatory skin disease common in summer or hot environment. In a hot environment, a large amount of sweat is not easy to evaporate, impregnation of the skin leads to blockage of the sweat ducts, resulting in the occurrence of small pimples, blisters, the patient usually in the neck, shoulders, back, chest and other places can be itchy. 3. Cholinergic urticaria: small windy skin disease caused by the release of acetylcholine from the peripheral nerves, can be found on the trunk and limbs when drinking hot food, taking hot baths, saunas and other hot times, accompanied by intense itching. When the body itches when hot, the patient should promptly consult a doctor to identify the cause of the disease, and the doctor should carry out targeted treatment. At the same time, you can locally use wet cloth wet compresses on the lesion area, avoid scalding, so as not to aggravate the symptoms of itching.