A person support apparatus includes one or more thermal image sensors whose outputs are analyzed to perform one or more functions. Such functions include automatically turning on a brake, automatically turning on one or more lights, detecting when a patient associated with the person support apparatus has fallen, enabling a propulsion system of the patient support apparatus to be used, automatically controlling one or more environmental controls, and/or automatically arming an exit detection system after entry of a patient onto the person support apparatus. Multiple thermal images may be generated from multiple sensors to generate stereoscopic thermal images of portions of the person support apparatus and its surroundings.