The fever of 39.5℃ in September belongs to high fever, parents are recommended to actively reduce fever treatment, antipyretic drugs can choose ibuprofen or acetaminophen, two drugs can choose one, after taking antipyretic drugs, parents should give the child more warm water, let it sweat, which is conducive to cooling, but be careful not to sweat too much, so as not to cause hypothermia or dehydration. Remind parents that if their child has recurrent fever, they must take the child to the hospital to see if the fever is caused by bacterial infection, viral infection, or mycoplasma infection, and whether the infection is in the respiratory system, digestive system, or urinary system, and to do routine blood, C-reactive protein, urine routine, chest X-ray, and other related tests to treat the cause.