Abstract: A rotor (10) for a rotating electrical machine is disclosed. The rotor comprises a plurality of salient poles (12) and rotor windings (22, 24) wound on the salient poles. A cooling vent (26) is provided through the rotor windings, the cooling vent extending through the rotor windings in an axial direction and a radial direction. The cooling vent (26) extends in an axial direction from one end of the rotor pole to the other. The cooling vent (26) may be formed by a plurality of discontinuous spacers (28), or by a spacer (78) which extends continuously around the rotor pole (12). Providing a cooling vent which extends through the rotor windings in an axial direction and a radial direction may help to improve the thermal performance of the machine in efficient and cost-effective manner.