The Refrigerator/Incubator Module (R/IM) is a temperature-controlled holding unit flown in the Shuttle middeck. It can be used in place of a standard middeck stowage locker or mounted to the Spacelab Middeck Experiment rack.

The R/IM uses a solid-state heat pump to maintain a cooled or heated internal environment. A fan circulates cabin air through the heat pump/heat sink and is exhausted through ducts in the top and bottom surfaces of the unit's outer shell. Air is not circulated within the internal cavity. A vent valve on the front door automatically controls internal pressure. To accommodate experiments, rail guides and fasteners are provided as a means of mounting up to six shelves of experiment hardware. The interior of the R/IM is divided into two holding cavities.