A switching device includes first and second RF terminals disposed over a substrate, one or more strips of phase change material connected between the first and second RF terminals, a region of thermally insulating material that separates the one or more strips of phase change material from the substrate, and a heater structure comprising one or more heating elements that are configured to control a conductive connection between the first and second RF terminals by applying heat to the one or more strips of phase change material. Each of the one or more strips of phase change material includes a first outer face and a second outer face opposite from the first outer face. For each of the one or more strips of phase change material, at least portions of both of the first and second outer faces are disposed against one of the heating elements.