Any affection produced by the action of the sun on some part of the body; especially, a sudden prostration of the physical powers, with symptoms resembling those of apoplexy, occasioned by exposure to excessive heat, and often terminating fatally; coup de soleil.

A serious failure of the body's heat-regulating mechanism resulting from excessive exposure to intense heat. Also called heat stroke.

sudden prostration due to exposure to the sun or excessive heat

Sunstroke is the name of a Marvel Comics supervillain.