Radiant heating systems directly heat the floor or panels in the wall or ceiling of a house, rather than heating the air, as do forced-air heating systems. The technique can be likened to standing in full sun on a chilly day, or feeling the warmth of a distant bonfire even though the air is cold. Despite the name, radiant heating systems also depend on convection — the natural circulation of heat within a room — caused by heat rising from the floor.