A memory cell includes a first electrode and an opposing second electrode, and a memory stack between the first and second electrodes. The memory stack includes a first layer of thermal isolation material contacting the first electrode, a second layer of thermal isolation material contacting the second electrode, and a phase change material between the first layer of thermal isolation material and the second layer of thermal isolation material. In this regard, the phase change material defines an active region width that is less than a width of either of the first layer of thermal isolation material and the second layer of thermal isolation material.