A child’s persistent fever of 39℃ may cause symptoms of convulsions and seizures, which may result in brain damage, i.e., burning out the brain. When a child has a persistent fever of 39 ℃, it means that there is a serious infection or other diseases in the body, if the high fever persists, it will have an impact on the nervous system, which may lead to convulsions and seizures, which may cause some damage to the brain cells, and even affect the normal development of the child and so on. Therefore, children with persistent fever of 39 ℃, need to go to the hospital in a timely manner, under the guidance of the doctor to give ibuprofen and other drugs to reduce fever, can be coupled with physical methods such as the head of the antipyretic stickers and other synergistic cooling. At the same time to clarify the cause of the disease, according to the original disease for targeted treatment. The use of medication should follow the doctor’s instructions.