This document provides an overview of fever, including its definition, types, causes, pathogenesis, and approach to evaluating a febrile child. It defines fever and describes the body's normal thermoregulatory responses. It outlines different types of fever based on period, degree, and pattern. The document discusses various infectious and non-infectious causes of fever and hyperthermia. It also describes the pathogenesis of fever involving pyrogenic cytokines and prostaglandins. The document outlines different presentations of fever including those with localizing signs, without localizing signs, and fever of unknown origin. It discusses evaluating a febrile child through history, physical exam, diagnosis, and laboratory tests.