Children who do not have fever during the day and have fever at night should be alert to the occurrence of acute gastroenteritis, upper respiratory tract infection, and childhood tuberculosis. 1. acute gastroenteritis: may be due to the child at night before going to bed to eat unclean food, will lead to acute gastroenteritis, fever, accompanied by diarrhea, abdominal pain clinical manifestations. 2. Upper respiratory tract infection: Upper respiratory tract infection is an important cause of fever at night but not during the day, mostly induced by viruses, bacteria and other microbial infections. 3. Children’s tuberculosis: most common in pulmonary tuberculosis, manifested by low fever, night sweating (abnormal sweating after sleeping, waking up sweating stops), emaciation, may also appear in children do not have fever in the daytime, fever at night. If the child does not have a fever during the day but has a fever at night, it should be closely observed, and if there is any abnormality, consult a doctor in time and follow the doctor’s instructions for targeted treatment.