If you do not have a mask, try not to go out, mainly to avoid the possibility of being infected. If you must go out without a special mask, you can also use the simplest cotton mask, which has a more limited role in preventing viruses and bacteria, but can filter droplets or aerosols to a certain extent, which also has a preventive role to a certain extent, but because the role is more limited, you can use two or three layers, which can improve efficiency. Also pay special attention to the environment outside, do not go to the crowded or more complex environment, such as try not to go to the market or hospital. Content source: Dr. You Lai