a turbomachine , in particular a steam turbine , has a shield and a coolant supply which causes cold intermediate superheater steam to flow onto the rotor , wherein additionally supply holes are arranged in the shield , which holes bring part of the hot inflow steam into the cooling region between the shield and the rotor , in order to thus improve mixing so as to raise the temperature of the rotor at this thermally loaded point , such that in the event of a fault the resulting change in temperature is moderate .