The present invention relates to a drug delivery device and in particular to temperature sensitive labelling of such devices. The drug delivery device is designed for dispensing of a dose of a medicinal product and includes a housing, and a drive mechanism comprising an axially displaceable piston rod to act on a piston of a cartridge containing the medicinal product to be dispensed. The device is further provided with an indicator adapted to irreversibly change at least one of its visually perceptible properties in response to the ambient temperature rising above and/or dropping below at least one predefined threshold. The indicator is preferably designed as a protective cover arranged across a functional component of the device.
