A young child with a fever of 39.5 degrees, but the mental state is good, it is recommended to find the cause of the fever, at the same time antipyretic drugs treatment. 1. Find the cause of the fever: a child with a fever of 39.5 degrees belongs to the high fever, although the mental state is good, but still suggests that there is a disease in the body caused by the need to actively look for the cause of the fever, for the cause of treatment, such as bacterial infections, the need for the use of penicillin, cephalosporin class antibacterial drugs. 2. Anti-fever medication: The neurological development of young children is not perfect, persistent high fever, may appear high fever convulsions, prolonged fever will also appear headache, dizziness and other uncomfortable symptoms. Therefore, it is recommended to use ibuprofen and other antipyretic drugs to reduce fever. If your child has a fever of 39.5 degrees, you need to take your child to the hospital in time to take antipyretic medication and find the cause of the illness.