Abstract: The atmosphere of a refrigeration space of a food transport vehicle is controlled by cooling the interior space to a preselected temperature by spraying liquid nitrogen within the space. After discontinuing the spraying, liquid nitrogen is conducted through a heat exchanger which extends across a portal communicating the space with ambient air. A ventilator forces air through the portal and the heat exchanger and into the space, whereby the ambient air is cooled and displaces gaseous nitrogen from the space. This creates a cold breathable atmosphere within the space to enable food to be loaded or unloaded. During the loading/unloading operation, liquid nitrogen can be conducted through an evaporator disposed in the space to maintain the temperature in the space.