Hot weather hand small bubbles (i.e. “blisters”), may be related to contact dermatitis, may also be due to eczema, herpes sweat and other diseases. 1. contact dermatitis: due to the hot weather, hand sweat more, hand skin for a long time by the sweat impregnation, resulting in increased sensitivity of the hand skin, in this case, after contact with detergents, chemicals and other objects, is likely to cause contact dermatitis, may cause the hands of erythema, blisters, etc., often accompanied by itching, and so on. 2. Eczema: the cause of the disease is not yet clear, is inside and outside a variety of factors leading to inflammatory skin diseases, may be related to genetics, the environment, infection, immunity, etc., resulting in small blisters on the skin of the hands, but also can be accompanied by obvious itching, pain and other symptoms. 3. Sweat herpes: the cause of the disease is not yet clear, may be related to heredity, allergies, immunity, etc., palm and plantar excessive sweating may also trigger the disease, especially in the case of hot weather is prone to sweating herpes, resulting in hot weather hands with small blisters, can be accompanied by dandruff, itchy, pain and other symptoms. Hot hands with small blisters, may also be caused by other reasons, it is recommended that the patient as soon as possible to the regular hospital, after a clear diagnosis, under the guidance of the doctor to give targeted treatment.