A persistent low-grade fever is not necessarily a novel coronavirus infection, and the accompanying symptoms, as well as the results of nucleic acid testing, are needed to confirm the diagnosis. There are many diseases that can cause low-grade fever, including the common cold, some patients with influenza, as well as patients with rheumatic fever, tuberculosis, and neocoronavirus pneumonia, of which influenza and rheumatic fever are more likely to have low-grade fever that does not go away. Fever due to neococcal pneumonia is more common as moderate fever or high fever. If there is only one symptom of low-grade fever, the chance of novel coronavirus infection is relatively small, and needs to be analyzed in conjunction with the epidemiological history, concomitant symptoms, and ancillary nucleic acid test results. If there is a history of contact with people in the infected area, or if one has traveled to the infected area and becomes ill with fever, the chance of novel coronavirus infection increases. Being affected by the epidemic, once fever symptoms appear, it is necessary to go to the fever clinic and do nucleic acid test for novel coronavirus to rule out novel coronavirus. Note: The terms “new coronavirus pneumonia” and “new coronavirus pneumonia” mentioned in this article were renamed to “new coronavirus infection” on December 26, 2022, as announced by the National Health Commission.