A fever is defined as a rectal temp over 100.4° F. Fever occurs when the hypothalamic thermoregulation center resets the temperature set point in response to a chain of events initiated by the inflammatory response. Glass thermometers remain the gold standard and electronic thermometers are generally acceptable, but studies do not consistently support the use of Infrared ear thermometers in children under 3. Evaluation of the sick child Includes observation, assessment of age and temperature risk factors, history and physical, and lab tests. To aid in the assessment of how ill or “toxic” a child appears, the Yale Observation Scale is used. Acetaminophen remains the antipyretic of choice. Febrile seizures are generally benign. Tepid sponge baths are only slightly more effective than acetaminophen alone in reducing fevers, but may be useful for children with a history of febrile seizures or liver disease. While there are many causes of pediatric fevers, they can be grouped into three general categories: fever with localizing signs, fever without localizing signs, and fever of unknown origin. Children with a localized infection are treated with antibiotics, antipyretics, and parent education; children with fever of unknown origin are referred for more In-depth evaluation. The management of children presenting with fever without a source is discussed in detail.