Fever is a familiar term used by the general public to describe an increase in body temperature above the normal range, typically due to an underlying cause such as an infection or inflammation. Whereas, pyrexia is the term preferred in clinical and medical settings, emphasizing the diagnostic aspect of fever. Pyrexia is the medical term for fever, in which the human body temperature rises above the average normal (37 degrees Celsius or 98.6 degrees Fahrenheit). Pyrexia is one of the most common symptoms of numerous medical conditions. Looking for online definition of pyrexia in the Medical Dictionary? pyrexia explanation free. What is pyrexia? Meaning of pyrexia medical term. What does pyrexia mean? Pyrexia, commonly known as fever, is the body’s natural defense mechanism to fight off infections and illnesses. Knowing the types, and symptoms behind Pyrexia can help in accurate diagnosis and effective treatment plans.