What is the clinical term for fever?

The clinical term for fever is pyrexia. Pyrexia refers specifically to an elevated body temperature that is typically a result of the body fighting an infection or illness, suggesting a physiological response. When the body temperature rises above the normal range (generally 98.6°F or 37°C), this often indicates that an underlying condition, such as an infection, is present, and it is the term most commonly used in a clinical setting to describe this phenomenon.

While "febrile" describes a state of having a fever, it is an adjective rather than a noun that directly refers to the condition itself. Therefore, while related, it does not serve as the formal clinical term for fever. Hyperthermia refers to an abnormally high body temperature due to external factors, while hypothermia refers to an abnormally low body temperature. Neither of these terms accurately describes the clinical condition of a fever. Thus, pyrexia is the most precise and appropriate term to denote fever in a medical context.