a closed first circuit configured as a compression refrigeration machine including a refrigerant as a first carrier medium, an evaporator configured as a liquid-liquid heat exchanger, a condenser configured as a liquid-liquid heat exchanger, a compressor, and a restrictor, said first carrier medium passing from said evaporator through said compressor to said condenser and from said condenser through said restrictor back to said evaporator;

a closed second circuit including said evaporator, a compressor, a fan, a heat exchanger and a liquid second carrier medium for transporting heat, said second carrier medium passing from said heat exchanger through said compressor to said evaporator and from said evaporator back to said heat exchanger of said closed second circuit;

a closed third circuit including said condenser, a first heat exchanger, a second heat exchanger, a liquid third carrier medium for transporting heat, and a compressor, said third carrier medium passing from said condenser through said compressor to said second heat exchanger and from said second heat exchanger through said first heat exchanger back to said condenser;

said closed second circuit being coupled by said the evaporator to said closed first circuit;

said closed first circuit being coupled by said the condenser to said closed third circuit;

said closed second circuit configured to cause, for cooling purposes, heat to be extracted at a predetermined location and transferred to said second carrier medium, the heat being carried by said second carrier medium to said evaporator for transferring heat to said closed first circuit;

said closed first circuit configured to cause heat to be transferred by said evaporator to said first carrier medium and passed by said first carrier medium to said condenser for releasing heat to said closed third circuit;

said second heat exchanger of said closed third circuit configured for cooling traction systems of the traction vehicle and for supplying heat of the traction systems to said third carrier medium; and

said closed third circuit configured to transfer heat of said closed first circuit through said condenser to said third carrier medium and to transfer heat, together with the heat of the traction systems, through said first heat exchanger to the environment.