A turbine, and particularly a low pressure turbine is disclosed, which comprises a plurality of rotor members and spacers for arranged between rotor members, to avoid that an ingested gas flow from the hot gas flow path channel reaches the wheel space. The rotor members each include a deflector. The deflector is placed in correspondence with each spacer and deflects the purging air pumped up from the wheel spaces by the rotor members, to prevent the ingested gas flow to heat up the roots of the blades.