The face is red and hot when exposed to the sun, the first consideration is due to prolonged exposure to the sun resulting in subcutaneous vasodilatation of the face, accelerated blood circulation due to the performance, is a normal physiological manifestation, does not require special treatment. If the symptoms are serious, or continue without relief, consider the pathological reasons, such as solar dermatitis, photosensitive dermatitis and other diseases. 1. Solar dermatitis: UV intensity is high, the skin epidermis is thin, accept sunlight, the skin is stimulated, an inflammatory reaction may occur, resulting in sunburn, the appearance of the sun a sunburn face red hot performance, may also be accompanied by erythema, blisters, local burning sensation, itching and other symptoms. Should avoid sun exposure, pay attention to sun protection, give symptomatic treatment. 2. photosensitive dermatitis: the disease is the patient’s allergy to ultraviolet light or the use of exogenous photosensitive substances caused by contact with ultraviolet light after the occurrence of an allergic reaction, so that the sun a sunburned face red hot, can appear erythema, pimples, doughnuts and other morphology of the skin lesions, accompanied by itching, tingling, swelling and other symptoms. It is necessary to do a good job of sun protection and give anti-allergy treatment under the guidance of a doctor. It is recommended that patients with red and hot face after sun exposure should pay attention to sun protection in daily life, and if accompanied by other uncomfortable symptoms, it is recommended to go to regular hospitals in a timely manner for a clear diagnosis and standardized treatment under the guidance of the doctor.