There is provided a lighting device 100 comprising at least one LED-based light source 102 for generating light, and a light exit element 101 which is optically and thermally coupled to the LED-based light source. The light exit element comprises a heat conducting structure 150 arranged for distributing heat generated by the LED-based light source over a predetermined sub area of the light exit element. The heat conducting structure may be embedded in or thermally connected to the light exit element and comprises aligned heat conducting paths 151. The introduction of heat conductive structures into the light exit element that spread heat in the light exit element and may be arranged to conduct heat from a heat sink into the light exit element or from the light exit element to a heat sink makes the light exit element to an integral part of the heat transferring external surface of the lighting device.