Abstract: A thermally responsive electric switch has an open ended, cup shaped, thermally and electrically conductive housing containing a thermostatic disc. A base of electrically insulative material, mounting a stationary contact arm, is received in the open end of the housing and captures an end of a movable contact arm between the base and the housing. The movable contact arm extends through a window in the stationary contact arm and has an opposite end disposed adjacent to the outer periphery of the disc and is adapted to be moved by the disc when it snaps from an unactuated to an actuated configuration to thereby control switch actuation.