A bulb-and-capillary type temperature sensor move a fulcrummed lever arm for effecting tripping of a snap-acting switch. The lever arm has a resilient bimetal strip cantilevered thereon which is biased at its free end away from the lever by an adjustment screw threaded through the lever arm. The lever arm contacts the temperature sensor and the bimetal strip contacts the switch for transmitting lever amplified sensor movement for switch actuation. The bimetal strip serves the dual function of ambient temperature compensation of switch calibration and absorbs sensor over-travel after switch tripping.