A skin-patch type large volume drug delivery device (1) comprising a heat exchanger (24) to extract thermal energy from the body/skin surface of the user and to supply the extracted thermal energy to increase the temperature of the medicament. Alternatively or in addition, a Peltier element (35) can be used for the same purpose. The device includes a temperature sensor (31) and a controller (16) for varying the flow rate within the heat exchanger as a function of the drug temperature.