Abstract: A portable heating unit has a heating chamber which is disposed within a housing so substantially all of the exterior thereof is displaced inwardly from that housing to define an air space. Air passing through that air space absorbs heat from the exterior of that heating chamber and also absorbs, and carries away, heat radiated from that exterior. That heating chamber is secured to that housing by mountings of small cross sections, which limit the amount of heat that can be conducted from that heating chamber to that housing. In addition, a baffle is interposed between the heating element and housing of the portable unit to reduce the amount of heat passing to that housing.