The line comes from Half-Life, Valve's 1998 first person shooter, where Gordon Freeman's HEV suit monitors health, armor and hazards. Its automated female voice gives status updates throughout the game, turning critical damage into a memorable danger alarm players heard during the toughest fights. As Half-Life clips and mods spread online, the warning was lifted from gameplay and reused outside the game. It remains popular because the phrasing is instantly recognizable to shooter fans, yet clear enough for anyone to understand as a last second health warning in edits and memes.