The correct way to wear a medical surgical mask is as follows: (1) Nose clip side up, dark side out (or pleats down) (2) Pull the pleats up and down so that the mask covers the mouth, nose and jaw. (3) Place the fingertips of both hands along the metal strip of the nasal bridge, from the middle to the sides, and slowly press inward until it fits snugly on the bridge of the nose. (4) Adjust the mask appropriately so that the perimeter of the mask fully fits the face. Disposable medical masks are recommended to be replaced once every 4 hours; N95 medical protective masks are recommended to be used for 6-8 hours. When replacing the mask, do not touch the outside of the mask with your hand, and remove the mask directly from the ear. Be careful not to touch the front of the mask and put it into the garbage bag by pinching the lacing with your hand. After removing the mask, wash your hands immediately, pay attention to hand hygiene, and replace the mask promptly if it becomes wet or contaminated with secretions.