Children’s body temperature of 39.4℃ belongs to high fever, which is more serious under high fever state, and it is easy to have febrile convulsions and convulsions under high fever, which will cause damage to the child’s brain cells and have certain effects on the intelligence of the child. So high fever state must actively take antipyretic treatment, can give oral antipyretic drugs or use antipyretic suppository treatment, and at the same time should actively cooperate with physical cooling, such as drinking water or using antipyretic paste to assist in reducing fever, together with treatment. If the child’s temperature does not drop to normal after oral medication and physical cooling, the child should be taken to the hospital for further treatment with antipyretic medication, or intramuscular injections or intravenous fluids. If the child continues to have a high fever of 39.4℃, it may also lead to the formation of myocarditis or myocardial damage, which may lead to chest tightness, weakness and shortness of breath, and may also affect the child’s future activities in life.