Abstract: A thermal protective barrier is provided for space heating units in the form of a relatively thin panel having an interior volume filled with a non-combustible liquid (water and/or antifreeze mix, etc.). Two of the embodiments are flat and are adapted to be placed beneath and about the sides of a stove or other heating unit, with a third embodiment having a toroidal cross section and being adapted for installation about the flue of such a stove or heater. Additional structure may be installed within the panels to provide additional support, as required. The panels may be removably installed between the stove and adjacent walls and the underlying floor, or may be permanently installed integrally with the building structure. The panels may also include decorative coverings for exposed surfaces, if desired. The panels may be independent of other water or fluid systems, or may be interconnected with a water heater or hot water heating system, if desired.