A thermally responsive switch and method for making the same in which a pair of contact elements including at least one bimetallic element are mounted within an integral support base molded from a mass of thermosetting material which is cured at the desired operating temperature for the switch. The contact elements each have a protruding stop and are biased during manufacture such that the stops abut the support base while the contact ends are maintained in a predetermined relationship with each other whereby the switch is calibrated at the same time the thermosetting material is cured.