Abstract: Cryogenic cooling system for transport vehicles. The cooling system includes an oversized ceiling evaporator, with adjustable heat absorption capability and pressure regulating mechanism, supplied with liquid CO.sub.2 from a main insulated reserve tank through a fill tank which balances the pressure of the liquid CO.sub.2 to the proper levels in order to permit the transfer of the refrigerant. To ensure this transfer, a gas-driven pump, activated by the CO.sub.2 gas exhaust from the evaporator, circulates the liquid CO.sub.2 inside the system. In addition, to ensure a quick stabilization of the temperature of the enclosure, a timed dry-ice injector acts as a booster and safety device to the system.