An assembly for evaporating a volatile fluid is described, the assembly comprising a device and a refill which are detachable from one another: wherein the device comprises a magnetic induction coil configured to operate with an alternating current passed therethrough at a frequency of between substantially 20 KHz to substantially 500 KHz and a volatile fluid transport means receiving area containing at least one piece of heat-conducting, non-magnetic metal foil and/or deposited heat-conducting, non-magnetic metal and wherein the refill comprises a reservoir for the volatile fluid, a volatile fluid transport means to draw the fluid from the reservoir, and at least one magnetic susceptor having a coercivity of substantially 50 ampere/metre (HC) to substantially 1500 ampere/metre (HC). arranged to heat the wick predominately by magnetic hysteresis when said alternating current is passed through the induction coil, wherein the refill is attached to the device such that at least one magnetic susceptor is at least partially located within the volatile fluid transport means receiving area. Refills, devices and methods of operation are also described.
