Apparatus for the control of flow and temperature of a working gas to allow temperature control of meal components carried by a two-compartment tray. The components of a meal are carried in an insulated, two-compartment tray. Both compartments are cooled by refrigerated air introduced thereto until a short time before serving. Then, hot air is introduced to one compartment to heat the contents thereof while the cool air flow to the other compartment is maintained. A flow distributor has two inlet and two outlet manifolds. One inlet and outlet manifold pair always receive cool air for supply to one compartment of the tray. The other inlet and outlet manifold pair can selectively receive either cool or hot air to allow heating or cooling of the contents of the other tray compartment. The trays are held in a uniform vertical array. Nozzles are connected to the air flow within the manifolds. The nozzles plug into the tray compartments to allow the air flow within the manifolds to control the temperature of the tray contents. Valves may be used to keep closed nozzles which do not have a tray presented to their position.