Hot weather limbs easy red spots itchy, may be related to papular urticaria, cholinergic urticaria and contact dermatitis, in the treatment is mainly targeted to give anti-allergic anti-itch medication, at the same time pay attention to strengthen the skin care. 1. papular urticaria: is due to mosquito bites and lead to an allergic disease, and environmental temperature increases, mosquito bites, so the hot season is also the papular urticaria stage. In terms of treatment, you can target some anti-allergic anti-itch medications, such as oral loratadine tablets, topical dinaid cream. 2. Cholinergic urticaria: It is a special type of urticaria, which is related to the increase of environmental temperature and the increase of skin temperature caused by various reasons. In the treatment, the main purpose is to give loratadine tablets and other anti-allergic drugs, and it can also be combined with vitamin C and calcium gluconate treatment. 3. contact dermatitis: refers to the skin in contact with some stimulating substances and produce allergic reactions, because the limbs belong to the exposed parts of the skin, so it is also the contact dermatitis parts, in the treatment of the main is the local topical anti-allergic mainly, such as fluoride acetate easy ice cream. The weather is hot limbs easy red spots itchy may have other reasons, in accordance with the doctor’s instructions to give medication at the same time, must pay attention to hygiene, keep the skin clean, suggest that the patient in a timely manner, under the guidance of the doctor to standardize the treatment.