The redness of the face when it is hot is considered to be due to the thinner facial stratum corneum, rich blood flow, but it may also be due to perimenopausal syndrome, solar dermatitis and other diseases. 1. Thin stratum corneum: people’s facial nerves are more abundant, but due to individual differences, some people’s facial stratum corneum is thin, so when the face is hot, the capillaries dilate, and you will see the face is red. 2. Perimenopausal syndrome: mostly seen in women aged 45 to 55 years old, can be due to the decline in ovarian function, sex hormone levels gradually decline, leading to neuroendocrine changes in the body, which changes in vascular diastolic function, can cause peripheral blood vessel dilation in the face, blood flow increases, redness. 3. solar dermatitis: solar dermatitis patients after intense sunlight exposure, sun exposure at the skin will occur acute phototoxic reaction, resulting in patients face, arms and other parts of the burning sensation, redness, swelling and other phenomena. The face of a hot red may be caused by other reasons, it is recommended to consult a doctor in a timely manner, to exclude physiological factors, as soon as possible to comply with the doctor’s instructions standardized treatment.