Close contacts or suspected exposed persons must be placed under medical observation. Medical observation includes home isolation medical observation and centralized isolation medical observation. 1. The body temperature does not exceed 38℃ and there are no obvious symptoms such as shortness of breath and suffocation; 2. The age is below 60 years old or above 5 years old; 3. The person is not pregnant, chronically ill or obese. If you belong to the above cases, it is recommended to rest and observe at home first. While you are at home, please drink plenty of water and you can take some cold medicine to reduce the symptoms. At the same time, take measures to protect yourself and your family by wearing a mask, washing your hands regularly, and ventilating your room regularly. At present, the main measure adopted around the world is home isolation medical observation. The period of medical observation is 14 days after the last unprotected contact with the case or suspected exposure. Those who do not develop the disease at the end of the observation period can resume normal study, work and life.