Physiological saline on the face, generally about 20 minutes is better. The main purpose of using physiological saline on the face is to increase the hydration of the skin surface, not only to moisturize, but also to clean up the skin, sterilize, remove oil and improve the effectiveness of pathological skin. If the face itself has skin pathology symptoms of erosion, exudation, blister-like changes, you can use physiological saline wet compresses for 20 minutes, which can make the appearance of erosion and exudation gradually improve, dry, and also dry out the blisters. From the dermatological point of view, the use of saline wet compresses, mainly as an adjunct to other treatments, can play a role in astringent exudation. When using saline wet compresses, it is best to use sterile gauze as an intermediate medium, and the gauze can be moistened. After the wet compress is completed, a moisturizer can be applied to avoid drying the face even more after the wet compress is finished.