Abnormally high body temperature or a disease characterized by it. It most often occurs with infection. Normal core body temperature, measured orally, does not exceed 99°F (37.2°C). Up to 105°F (40.6°C), fever causes weakness and is best treated with aspirin, acetaminophen, or other antipyretic drugs. At 108°F (42.2°C) or more, it can lead to convulsions and death. In treatment, it is important to know the underlying cause. Fever appears to be a defense against infectious disease, stimulating leukocytes and increasing antibody production and perhaps killing or inhibiting bacteria and viruses that live within a narrow temperature range.