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.