Abstract: Disclosed is a lighting unit comprising at least one light emitting diode (50), means for supplying power to the light emitting diode (50), and a motor driven pump means (18) for generating a stream of fluid for cooling the light emitting diode (50). The pump means is mounted in a resiliently compressible member (48) for absorbing vibrations produced by the pump means (18) which reduces the level of noise produced by the lighting unit. The lighting unit has control means operable to gradually increase or decease the speed of operation of the pump means in response to the power dissipation of the light emitting diode exceeding or falling below, respectively, a threshold level, which makes the noise produced by the pump means less noticeable.