Recurrent fever in acute upper respiratory tract infections indicates that the bacteria or virus causing the upper respiratory tract infection is not under control or that other complications have arisen. When a bacterial or viral infection exists in the body, the bacterium or virus acts as an exogenous pyrogen, which is recognized by immune cells in the body, causing them to produce and release endogenous pyrogens, which act on the thermoregulatory centers and cause the body’s local or systemic body temperature to rise. Fever can promote the migration of immune cells to the site of infection, enhance the phagocytosis of immune cells, and thus eliminate pathogens. Therefore, fever is the body’s self-protection mechanism. When acute upper respiratory tract infection recurrent fever, on the one hand, it is because the pathogens in the body are not completely cleared, or the infection is aggravated, resulting in the presentation of recurrent fever symptoms. Due to the different types of fever caused by different bacteria or viruses, some pathogens such as Plasmodium, Borrelia burgdorferi, Spirochaete regurgitans, etc. cause the body to alternate between periods of high fever and periods of no fever, resulting in recurrent fever. It is also important to pay attention to the possibility of complications, such as colds secondary to otitis media and sinusitis, or a combination of other diseases that can lead to fever, such as malignant tumors, connective tissue disease, and so on. If there is a fever, it is recommended to go to the hospital in time for treatment, and those who have recurrent fever should be examined comprehensively to clarify the cause and use medication accordingly.