Generally, it is not recommended to use hot water to wash the face when there is redness and itching on the face. Redness and itchiness on the face is considered to be dermatitis caused by allergy. If you wash with hot water, it may stimulate blood vessels and aggravate the redness and itchiness. Red, itchy face allergy causes more, may be dry weather, improper diet or the use of unsuitable cosmetics, such as facial cleanser, masks, etc., it is recommended to actively search for the cause, and targeted treatment. If it is caused by cosmetic allergy, it is necessary to stop using it immediately, and can be used externally to stop itching ointment, such as the commonly used 0.03% tacrolimus ointment. If the itching is more intense, you can take oral antihistamines to stop itching, such as kairatan, paracetamol, cetirizine hydrochloride. If the redness and itchiness are caused by dry weather and improper diet, it is enough to pay attention to skin moisturizing and stop eating allergic foods. Patients in the acute stage of symptoms need to wash their face with water, do not use facial cleanser, avoid the intense stimulation of hot water, so as not to lead to the aggravation of skin symptoms.