Children with fever up to 40 ℃, may be caused by upper respiratory tract infections and other causes, generally does not directly damage the brain function, but the need to promptly give the child fever, to avoid causing convulsions, dehydration and other adverse consequences. The child’s fever may be caused by upper respiratory tract infection, etc., at this time the brain thermoregulation center abnormal reaction, so that the temperature regulation point of the upward shift caused by a symptom. Body temperature in 37.5 ℃ -40 ℃ fluctuations, easy to induce febrile convulsions, and children’s immature development of the nervous system and genetics, manifested in the loss of consciousness, body stiffness, limb twitching, foaming at the mouth, etc., the duration of a short period of time, the general febrile convulsions will not damage the brain, affecting the intelligence and other development. However, if it lasts for several days and exceeds 42℃, it may cause permanent brain damage. Brain damage is more commonly caused by intracranial infections and other causes. When the child’s temperature exceeds 38.5 degrees, ibuprofen, acetaminophen and other medications can be given to reduce fever, and timely fever reduction can ease the discomfort caused by fever and reduce crying. If the fever is caused by bacterial infection, you need to follow the doctor’s advice to use amoxicillin and other antibiotic treatment to effectively control the fever, to avoid recurrence. When the child’s fever reaches 40 ℃, it is recommended to seek medical treatment.