Abstract: The invention relates to an arrangement in an interior panel (2) or the like having a rearwardly located space through which air which has been heated is arranged to flow, to eliminate the radiation of cold from a wall, a floor or the like. In accordance with the invention, the space is confined and divided into at least two thin air cavities (4,5), by means of an intermediate plate (3) which extends parallel to the interior panel (2) and which comprises a material having good heat-insulating properties. The heated air is arranged to be circulated in the air cavities, around the intermediate plate. A heater is provided for heating the air passing to the air cavity (4) adjoining the interior panel, to a temperature of at most some few degrees above the room temperature. A fan (10) is controlled by an air flow control regulator (10') which is actuated by a thermostat (14) which compares the temperature of the air as it moves out of the inner space (4) with the intended room temperature.