Asymptomatic low fever in children may be caused by chronic tonsillitis, hand, foot and mouth disease, pneumonia and other causes, but there may be no obvious symptoms in the early stage, for low fever can be taken to physical cooling and other ways. 1. Chronic tonsillitis: mainly bacterial infections, chronic tonsillitis symptoms may appear dry throat, bad breath and other conditions but not easy to detect, may appear low fever. 2. Hand, foot and mouth disease: mainly caused by infection of coxsackie and other viruses, usually in the early stage of the phenomenon of fever, after a day or two can appear herpes on the hands, feet and mouth. 3. Pneumonia: generally caused by infection with viruses, streptococcus and other pathogenic bacteria, the condition of the early stage may not appear obvious respiratory symptoms, but the body temperature will fluctuate, such as untimely treatment can be other diseases, such as coughing, coughing up sputum, high fever and so on. Asymptomatic low fever in children may also have other causes, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.