Fever is most often seen after infection with novel coronavirus and, as the first symptom in most infected patients, usually occurs within 14 days of exposure, with most patients presenting with a high fever of 39°C or more and a few with only a mild fever below 38°C. Regardless of the temperature, anyone with a clear history of exposure should promptly visit a fever clinic anywhere for a formal examination. Pathogenic testing is usually scheduled after chest x-ray (or CT) and routine blood test results show signs of viral pneumonia. Some patients with clear exposure and febrile symptoms should have pathogenic testing even if the imaging and blood work are not abnormal. Because some patients with mild disease do not show pneumonia manifestations but can spread the phenomenon, it is important to confirm the diagnosis in a timely manner and treat them in isolation so as not to cause more people to be infected.