A floor heating system (100) includes a flooring substrate (112) having a heating or cooling element (114) in heat transfer relationship therewith. A heat spreader (116) is in heat transfer relationship with the flooring substrate (112). The heat spreader (116) includes a layer of flexible graphite material. A floor covering (118) overlies the layer of flexible graphite material. Temperature variations across an exposed surface of the floor covering (118) are reduced by the presence of the flexible graphite heat spreader (116), thus providing an improved and more uniform heating to the floor and to the room with which the floor is associated.