An apparatus is provided for vaporizing a source of vaporizable substance for delivering an aerosol. The vaporizing apparatus comprises a housing defining a first combustion chamber, a second vaporizing chamber for receiving the vaporizable substance, and a transverse wall spanning the interior of the housing for separating the first chamber and the second chamber. A heat transfer element, comprising an elongated member of heat conductive material, extends from the first chamber through the wall and into the second chamber in heat transfer relation with the vaporizable substance for transferring heat from the first chamber to the vaporizable substance. A gas burner disposed in the combustion chamber converts fuel gas to a flame for heating the combustion chamber and the heat transfer element. The heat transfer element maintains the temperature in the second chamber at or above the vaporization temperature of the substance.
