An illuminating glazing unit for vehicles, including: a first transparent sheet of glass with a first main face, a second main face, and an edge; one or more modules including light-emitting diodes (LEDs), each including a plurality of LEDs and associated electronic components fixed to a printed circuit board, the modules being positioned such that emitting faces of the LEDs are turned toward the edge of the first sheet of glass; an encapsulation mechanism in contact with the first main face of the first sheet; a light extraction element, which can be located on one of the main faces of the first sheet of glass; and a heat sink element, in thermal conduction contact with the LED module, in contact with the encapsulation mechanism, and in contact with an atmosphere via a heat exchange surface.