Abstract: Disclosed is apparatus for keeping a vehicle operator awake by means of an audible alarm or signal responsive to a nodding or tilting forward movement of the head of the operator of the vehicle. The apparatus includes a switch mounted on a hat, ear hook or head band, worn by the vehicle operator and which switch is closed upon the tilting forward of the operator's head to complete an electrical circuit providing power from a battery to an alarm. The battery and alarm may be enclosed in a casing which may be clipped to the operator's wearing apparel, or mounted on the dash board of a vehicle and a flexible electrical line interconnects the hat, head band or ear hook and the casing or dash board to permit freedom of operator movement; also, an electrical connector may be provided on the flexible electrical line to permit the hat, head band or ear hook and casing or dashboard to be electrically and mechanically disconnected.