Fever is a reaction of the body to the stimulation of external pathogens or chemical and physical factors. Fever itself is not contagious, but the disease that causes it may be infectious, such as influenza, which can be spread through airborne droplets, and syphilis and AIDS, which can be spread through sexual contact. Fever as a symptom is not contagious. However, for patients with fever, it depends on what disease is causing the fever and through what means and sources of infection the disease is transmitted. For example, influenza can be spread through airborne droplets, while bacterial colds are not highly contagious. Tuberculosis, if in close contact, can be spread by airborne droplets, but extra-pulmonary conjunctive diseases such as bone tuberculosis, intestinal tuberculosis, and tuberculous meningitis are not contagious. Infectious diseases such as syphilis, AIDS, and hepatitis are often spread through sexual contact, blood contact, and mother-to-child transmission. Some enteroviruses, such as rotavirus, can cause symptoms such as fever, diarrhea, nausea, vomiting, etc. The virus is often transmitted through mouth-to-hand contact allowing pathogenic bacteria to enter the mouth. If the fever is contagious, it depends on whether the disease causing the fever is contagious or not. If the disease is contagious, the disease should be isolated and blocked according to the transmission route of the disease to avoid the spread of contagious disease epidemic causing fever.