In one aspect, apparatus is provided for generating an inhalable medium. The apparatus has a container for holding a liquid and a heater for volatilizing liquid held in the container. The apparatus further has a chamber for receiving a material. The apparatus has an outlet. In use liquid volatilized by the heater passes, in the form of at least one of a vapor and an aerosol, through material received in the chamber to thereby entrain one or more constituents from the material to produce the inhalable medium which passes out of the outlet.