Fever is a common reason children see doctors and causes concern for parents. A fever is defined as a temperature over 37.2°C before noon or 37.7°C after noon. Fever occurs due to infection, inflammation or injury and raises the hypothalamic temperature set point. While sometimes indicating a minor self-limiting infection, fever can also signal a serious disorder. The document discusses evaluating fever, defining related terms like bacteremia and sepsis, the pathophysiology of fever production, and methods for safely measuring a child's temperature.