The common causes of fever in children at night are infectious factors, i.e. viral or bacterial infections, non-infectious factors such as rheumatic diseases, thermoregulatory malfunctions, metamorphic reactions, etc., and also non-disease factors such as too high a room temperature and too many children’s clothes. 1. Viral infections: cause fever such as upper respiratory tract infections, hand-foot-mouth disease, measles, viral mumps, etc; 2. Bacterial infections: such as Streptococcus pneumoniae pneumonia, sepsis, enteritis, bacillary dysentery, purulent meningitis, purulent mumps and so on; 3. non-infectious factors: after extensive burns, leukemia, lymphoma, rheumatic fever, Kawasaki disease, allergic reactions, etc; 4. non-disease factors: room temperature is too high, the child wears too much can also lead to fever in small infants. Children have fever at night, there may be other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.