TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Method: The method (M1) further involves compressing the refrigerant vapor before it is condensed; and circulating a first cooling medium through an inlet in the evaporator (6), through a coil (9,10) in the evaporator and to an outlet of the evaporator, thus lowering the temperature of the first cooling medium as it passes from the inlet to the outlet of the evaporator, and passing the first cooling medium to a body to be cooled, thus producing cooling. The step of evaporating the refrigerant composition involves circulating the refrigerant composition through an inlet in the evaporator, through a coil in the evaporator, and through an outlet in the evaporator, thus lowering the temperature of a first liquid cooling medium contained in the evaporator, and passing the first liquid cooling medium out of the evaporator to a body to be cooled, thus producing cooling.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The composition comprising iodotrifluoromethane, difluoromethane, and hydrocarbon further comprises pentafluoroethane. The composition (C1) preferably comprises either (wt.%): iodotrifluoromethane (35), difluoromethane (55), pentafluoroethane (5) and propane (5); iodotrifluoromethane (35), difluoromethane (60), pentafluoroethane (2.5) and propane (2.5); iodotrifluoromethane (30-50), and 1,1,1,2-tetrafluoroethane (50-70); iodotrifluoromethane (5-35), 1,1,1,2-tetrafluoroethane (5-40) and difluoromethane (33-70); or iodotrifluoromethane (25-50), difluoromethane (40-60), pentafluoroethane (0-50) and 1,1,1,2-tetrafluoroethane (5-50). The composition further comprises a lubricant and at least one additive. Preferred Components: The hydrocarbon is preferably propane. The lubricant is mineral oil, alkylbenzene, synthetic paraffin, or synthetic naphthene. The additive is selected from compatibilizers, UV dyes, solubilizing agents, tracers, and stabilizers.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The lubricant is polyalkylene glycol, polyol ester, polyvinylether, or poly(alpha)olefin. The additive is perfluoropolyether, or functionalized perfluoropolyether. EXAMPLE - A composition (test) comprising (wt.%): difluoromethane (0.550), pentafluoroethane (0.050), propane (0.050) and iodotrifluoromethane (0.350) were prepared. The cooling performance, as energy efficiency (COP), cooling capacity, compressor discharge pressure, compressor suction pressure, average temperature glide (avg glide, which was the average glide for evaporator and compressor), global warming potential (GWP) value, and compressor discharge temperature for the composition as compared to chlorodifluoromethane (HCFC-22) (control) for low and medium temperature refrigeration system was tested. The test/control composition showed a GWP value: average glide ( degrees C): COP: cooling capacity (kJ/m3): compress discharge pressure (kPa): compressor suction pressure (kPa): compressor discharge temperature ( degrees C) of 474/2000: 2.27/0.00: 1.34/1.46: 2565/1697: 2794/1774: 460/267: 149.9/144.