A portable device which generates heat and which can be used alternatively as a corded, plug-in device or as a cordless, fuel-powered device. The device has dual heating capabilities — each of which is powered by a unique cartridge. For use as a plug-in device an electric cartridge that connects the device to an adapter is utilized, whereas for use as a portable device a fuel cartridge is utilized for supplying a hydrocarbon fuel to support combustion. Use of one of the cartridges prevents the use of the other.