In its simplest terms, refrigeration is simply the removal of heat from one medium to another by use of inert gas. In the case of refrigerated containers, it is removal of heat from inside the box - the cargo and surrounding air - to outside the box. The inert gas most commonly used is named R-12.
producing a cold climate within a closed space or chilling a substance to some point below its starting temperature.
Storing cigars in an airtight bag in a fridge is not recommended for at the very least the cigars will have to be returned to room temperature for at least 30 minutes before you can smoke them. More importantly, the cold will impair the flavour and aroma of a fine cigar. It's best to keep fine cigars away from extremes of cold or heat in a proper humidor.