The invention relates to a structure comprising a base (1) and a cover (2). Said base (1) is provided with an opening (3) that extends into a neck (4) which is used to connect the wick of the container when a liquid product is involved. Said neck (4) is housed inside another cylindrical neck (10) which is disposed in the cover (2) when in closed position, defining an annular housing containing arched partitions (11-11'). Said partitions are obtained by die-stamping the respective plates (12-12') which act as a radiator and which are provided with parallel blades (13) that are bent in an orthogonal manner. The PTC resistor (15) and a spring (16), which facilitates the electrical connection, are positioned between said blades, such that the plates (12) act not only as radiators but also as means for supplying electricity to the resistor (15), for which said plates are provided with connectors (16) that receive the corresponding cables.