A MEMS thermal switch is disclosed which couples a hot, expanding beam to a cool flexor beam using a slideably engaged tether, and bends the cool, flexor beam by the expansion of the hot beam. A rigidly engaged tether ties the distal ends of the hot, expanding beam and the cool, flexor beam together, whereas the slideably engaged tether allows the hot, expanding beam to elongate with respect to the cool, flexor beam, without loading the slideably engaged tether with a large shear force. As a result, the material of the tether can be made stiffer, and therefore transmit the bending force of the hot, expanding beam more efficiently to the cool, flexor beam.