The present invention relates to a heating and/or cooling assembly such as a heat pad. The assembly includes a plurality of modules articulated together by connection means so that the assembly can be manipulated by a user to adopt a desired profile. At least one of the modules contains a thermal store in the form of a solid, liquid or gel responsive to heating or cooling externally applied to the assembly so that the solid, liquid or gel is heated or cooled, respectively, and remains in a heated or cooled state for a prolonged period of time after the externally applied heating or cooling is removed.