What is the term for a significant increase in core body temperature?

The term associated with a significant increase in core body temperature is hyperthermia. Hyperthermia occurs when the body absorbs more heat than it dissipates, leading to dangerously elevated temperatures. This condition can arise from prolonged exposure to high temperatures, strenuous exercise in hot weather, or dehydration, and can result in severe health complications if not addressed promptly.

Heat exhaustion is characterized by symptoms like heavy sweating and weakness but does not necessarily indicate a critical rise in core body temperature. Heat stroke, which is a serious medical emergency, is actually a severe form of hyperthermia where the body's temperature can rise to 104°F (40°C) or higher, resulting in potential damage to the body's organs; however, the precise term for the initial significant increase is hyperthermia. Hypothermia, conversely, refers to dangerously low body temperature and is entirely unrelated to the concept of increased core temperature.