People who have been exposed to COVID-19 may be infected within 1 day, because people are generally susceptible to COVID-19, so the infection rate is faster. The incubation period of novel coronavirus is usually about 3-5 days, and the longest is 14 days. If you are infected with novel coronavirus, you may have abnormal symptoms such as dry cough, fatigue and fever after 3 days, but some patients have no symptoms after being infected with novel coronavirus. If you suspect that you are infected with novel coronavirus, you can go to the hospital for nucleic acid testing. Usually avoid going to crowded places to reduce the chance of being infected.