Abstract: A heated mold panel for casting concrete has a rigid base providing a base surface, a substantial part of which is grooved by interconnecting grooves, has a continuous heating element laid in the grooves, and the base surface is covered with a non-porous, non-corrosive material that provides a smooth outside surface covering the base surface, spanning the grooves and enclosing the element in interconnecting passages defined by the grooves and the covering material. Sufficient clearance is provided in said passages around the element for air to flow freely from passage to passage, whereby heat flow from the element to the concrete poured against the outside surface is by radiation from the element and by convection of air flowing in the passages around the element.