A thermally responsive switch and method for making the same in which a base container having a cover supports a pair of contact elements, including at least one bimetallic element, and is filled with a hardenable material cured at the desired operating temperature of the swtch to form an integral support base. The contact elements each have a protruding tab which cooperates with an interior wall of the base container so as to properly position the contact elements in the container after the cover has been attached, to close off the bottom of the container such that the hardenable material may be retained therein, and to cause the contact elements to pviot together at their contact ends under the force of gravity whereby the switch is accurately calibrated and the contact elements are protected during assembly.