A cooling system for a magnetic resonance tomography system is provided. The cooling system includes a first coolant circuit with a first coolant pump and a first heat exchanger in thermal contact with an object to be cooled. The first cooling circuit further includes a switchover apparatus that is configured to adjust a heat flow from the first coolant circuit optionally to a first heat sink and/or a second heat sink. In such cases the second heat sink is a second heat exchanger that is fluidically connected to an emergency cooling system.