Two-year-old baby fever 39.8 ℃ possible causes are bacterial infections, blood system diseases, catching cold, etc., in the physical and drug cooling treatment at the same time, according to the cause of dietary control, medication, conservative treatment and other methods to deal with. When the two-year-old baby fever 39.8 ℃ need to follow the medical advice to use ibuprofen, acetaminophen and other drugs for antipyretic treatment; also need to use warm water compresses on children’s foreheads, warm baths, reduce the wearing of clothing, antipyretic patches, antipyretic blankets, fans and reduce indoor temperatures, and so on, these methods through the conductive, convective and evaporative effects of the body to take away the heat, so that the fever children feel comfortable. It is also important to treat the cause of the illness to restore the body temperature. For respiratory tract infections caused by bacterial infections, antibacterial drugs such as cefaclor and cefdinir should be actively used for anti-infective treatment. If the disease is rheumatic immune disease, immunosuppressant treatment is needed; if the disease is related to blood tumor, chemotherapy, bone marrow transplantation and other treatments are needed. All of the above drugs should be used under the guidance of a doctor, avoid self-medication. It is recommended that children with fever should consult a doctor in time to be evaluated and treated by a specialist.