A cooling apparatus for an engine of a moveable vehicle , comprising: a heat-generating assembly of the engine being configured to generate heat once actuated to do just so; and a cooling system being configured to circulate a pressurized cooling medium including carbon dioxide relative the heat-generating assembly , characterized in that the cooling system includes a heat exchange structure surrounding the heat-generating assembly , the cooling system includes at least one intake assembly at which a pressure reducing device is operatively positioned which intake assembly is configured to deliver the cooling medium to the heat exchange structure , and that the cooling system includes a spray-generating device configured to increase the rate of heat energy absorption and to be operatively attached to the intake assembly , the spray-generating device generating droplets of the cooling medium , wherein at least one outlet assembly extending from the heat exchange structure and being spaced apart from the intake assembly , a control system for controlling temperature and pressure of the cooling medium, a closed-loop circulation circuit conveying the carbon dioxide cooling medium from at least one outlet assembly to a gas-liquid separator and the separated liquid phase component of the cooling medium to the at least one pressure reducing device , and wherein the mass flow of the cooling medium is controlled by the at least one spray-generating device and the at least one pressure-reducing device in a closed-loop proportional control of temperature and pressure under the operational control of the control system relative to the heat-generating assembly of the engine in such a way that the carbon dioxide as the cooling medium receives and conveys heat from the heat-generating assembly of the engine, and transports the heat away from the heat-generating assembly of the engine by way of evaporation of liquid carbon dioxide and absorbtion of heat. a heat-generating assembly of the engine being configured to generate heat once actuated to do just so; and a cooling system being configured to circulate a pressurized cooling medium including carbon dioxide relative the heat-generating assembly , characterized in that the cooling system includes a heat exchange structure surrounding the heat-generating assembly , the cooling system includes at least one intake assembly at which a pressure reducing device is operatively positioned which intake assembly is configured to deliver the cooling medium to the heat exchange structure , and that the cooling system includes a spray-generating device configured to increase the rate of heat energy absorption and to be operatively attached to the intake assembly , the spray-generating device generating droplets of the cooling medium , wherein at least one outlet assembly extending from the heat exchange structure and being spaced apart from the intake assembly , a control system for controlling temperature and pressure of the cooling medium, a closed-loop circulation circuit conveying the carbon dioxide cooling medium from at least one outlet assembly to a gas-liquid separator and the separated liquid phase component of the cooling medium to the at least one pressure reducing device , and wherein the mass flow of the cooling medium is controlled by the at least one spray-generating device and the at least one pressure-reducing device in a closed-loop proportional control of temperature and pressure under the operational control of the control system relative to the heat-generating assembly of the engine in such a way that the carbon dioxide as the cooling medium receives and conveys heat from the heat-generating assembly of the engine, and transports the heat away from the heat-generating assembly of the engine by way of evaporation of liquid carbon dioxide and absorbtion of heat. <EOS>