the.com/sunstroke

means A dangerous overheating of the body caused by prolonged exposure to intense sun or heat, marked by high fever, confusion, and collapse because sweating and other cooling mechanisms fail.

from A plain 19th-century compound of 'sun' and 'stroke' — 'stroke' here carrying its old sense of a sudden, blow-like attack, the same sense preserved in 'apoplectic stroke.' Heatstroke itself was recognized long before, but English fastened the sun specifically into the name once the condition became common lore among soldiers and laborers working bareheaded in blazing climates — the sun imagined almost as an assailant striking someone down.