Children with repeated fever for four days may not necessarily be leukemia, but may also be caused by other infectious diseases, to be determined according to the hospital examination results. Children with recurrent fever for four days are more likely to have viral infections, such as respiratory tract infections, gastrointestinal tract infections, urinary tract infections, etc. They should be examined by the pediatric department of a regular hospital for routine blood tests, and the diagnosed child can be treated with anti-infection therapy under the guidance of a doctor. If the child has a fever along with symptoms such as bleeding and anemia, he or she can go to the hospital for routine blood tests and coagulation tests, or even a bone marrow aspiration, to confirm whether the fever is caused by leukemia. In addition, malignant tumors or systemic lupus erythematosus may also cause children to have frequent fevers. Therefore, recurrent fever in children should not be ignored, and symptomatic treatment should be given after finding the cause in order to avoid delaying the disease. If the child’s body temperature is below 38.5℃, he or she can drink water several times in small amounts and use physical cooling to facilitate heat dissipation. If the body temperature is higher than 38.5℃, medication should be taken under the guidance of a doctor.