A device (100) for heating an aerosol-forming substrate includes a heater (160), a receptacle inlet (143) and outlet (147), and an air inlet channel (170). The heater includes a heating element, an internal surface, and an external surface. The internal surface defines at least a portion of a receptacle (140) configured to receive the aerosol-forming substrate or a cartridge comprising the aerosol-forming substrate. The receptacle inlet is in communication with, and upstream of, the receptacle. The receptacle outlet is in communication with, and downstream of, the receptacle. The air inlet channel is in communication with an ambient environment and the receptacle inlet. The air inlet channel defines a tortuous path between the ambient environment and the receptacle inlet. The air inlet channel is positioned relative to the heater to cause air in the tortuous path to be heated by the heater.