Sunstroke, also called heatstroke, is a medical emergency that occurs when your body temperature rises to 104 F or higher, overworking your organs, and can lead to death or permanent disability if not treated quickly.

Sunstroke and heatstroke are the same thing, but the term sunstroke is more commonly used to refer to heat-related illness caused by exposure to the sun, while heatstroke can also refer to heat-related illness caused by other sources of heat, such as industrial accidents.