A device and method are provided combining the thermal and mechanical attributes of two distinct materials: shape memory materials and super-cooled liquids (SCLs). In one example of the invention, the super-cooled liquid is contained within a shape memory polymer (SCL liquid is filled into a shape memory polymer tube), so that the heat released by the SCL when it is mechanically triggered to crystallize itself triggers the shape change of the shape memory polymer. The device is suitable as a reusable warmer, as a dental mold material, in medical applications where reusable heat packs are indicated, particularly for application to difficult contours, and for large deployable structures such as satellite antennae and temporary shelters.