The incubation period for novel coronavirus can be up to 21 days, and if the patient has an epidemiologic history, intensive isolation is generally required for 14-21 days, after which continued isolation at home for 1-2 weeks is still required. Therefore, if a person is at high risk for novel coronavirus pneumonia infection, 28 days of isolation does not necessarily mean that it is safe. Multiple consecutive novel coronavirus nucleic acid tests are required, and only if the test is negative and there are no symptoms such as fever, dry cough, or malaise, and confirmed by a physician, is the situation safe. High-risk patients are those who have a history of close contact with patients with novel pneumonia, or a history of residence or travel in moderate-to-high risk areas. Close contact means having close contact with suspected or confirmed patients or asymptomatic infected persons who have not taken effective protection, such as riding the same transport and having contact within 1 meter, eating at the same table, etc. The new coronavirus is highly contagious and has a long incubation period. Even if the patient is isolated for 28 days and the test results are normal, the patient cannot be considered absolutely safe, so the patient still needs to pay attention to physical changes. If the infection is a common respiratory bacterial infection, it can be treated with appropriate antibiotics, such as penicillin and azithromycin, under the guidance of a doctor. If the patient is confirmed to have novel coronavirus pneumonia, he or she needs to be isolated and treated in a timely manner.