An electric power-supply apparatus comprising: a cord and a plug for access to a source of electrical energy; a thermostat with contacts, wherein the thermostat is configured such that the contacts are closed if the ambient air temperature is below its set point but are open if the ambient air temperature is above its set point; a dehumidistat with contacts, wherein the dehumidistat is configured such that the contacts are open if the ambient relative humidity is below its set point but are closed if the ambient relative humidity is above its set point; and at least two receptacles that are configured to conditionally distribute electrical energy to one or more devices which are plugged into one or more of them, characterized in that: a) the apparatus comprises a circuit configured to bring electrical energy into the apparatus, and the thermostat and the dehumidistat are positioned on separate parallel paths of the circuit; b) the apparatus is configured to energize a first receptacle of the receptacles, for supplying power to at least one heater, if the apparatus itself is energized and the contacts of the thermostat are closed, but to not energize the first receptacle if the contacts of the thermostat are open; and c) the apparatus is configured to energize a second receptacle of the receptacles, for supplying power to at least one fan, if the apparatus itself is energized and the contacts of the thermostat and the dehumidistat are not both open. a cord and a plug for access to a source of electrical energy; a thermostat with contacts, wherein the thermostat is configured such that the contacts are closed if the ambient air temperature is below its set point but are open if the ambient air temperature is above its set point; a dehumidistat with contacts, wherein the dehumidistat is configured such that the contacts are open if the ambient relative humidity is below its set point but are closed if the ambient relative humidity is above its set point; and at least two receptacles that are configured to conditionally distribute electrical energy to one or more devices which are plugged into one or more of them, characterized in that: a) the apparatus comprises a circuit configured to bring electrical energy into the apparatus, and the thermostat and the dehumidistat are positioned on separate parallel paths of the circuit; b) the apparatus is configured to energize a first receptacle of the receptacles, for supplying power to at least one heater, if the apparatus itself is energized and the contacts of the thermostat are closed, but to not energize the first receptacle if the contacts of the thermostat are open; and c) the apparatus is configured to energize a second receptacle of the receptacles, for supplying power to at least one fan, if the apparatus itself is energized and the contacts of the thermostat and the dehumidistat are not both open. a) the apparatus comprises a circuit configured to bring electrical energy into the apparatus, and the thermostat and the dehumidistat are positioned on separate parallel paths of the circuit; b) the apparatus is configured to energize a first receptacle of the receptacles, for supplying power to at least one heater, if the apparatus itself is energized and the contacts of the thermostat are closed, but to not energize the first receptacle if the contacts of the thermostat are open; and c) the apparatus is configured to energize a second receptacle of the receptacles, for supplying power to at least one fan, if the apparatus itself is energized and the contacts of the thermostat and the dehumidistat are not both open.