A heating device (1) is described for a container (7) of a liquidpharmaceutical product having a viscosity of 50-500cP at 4°C and contained within a glass container. The device (1)comprises a substantially rigid, thin-walled housing (2) definingan openable chamber for receiving the container (7), a heat source (6) in thechamber comprising a hermetically sealed packagecontaining a super-cooled metal salt fluid or liquid and an actuator (14) foractivating the super-cooled metal salt to produce heat,wherein the ratio of the volume of the metal salt to the intended volume ofthe product is no more than 1:1.
