How does a refrigerator work?

You ask: How cold box work?

Cold box no make cold. Cold box steal heat from food and dump heat behind box. How? Special juice run in pipes around box, juice that boil at very low warm. When river water dry off Caveman skin, Caveman feel cold — turning liquid to vapor eat heat, and eat big: water need five times more heat to turn vapor than to warm from ice-cold all way to boiling. Same trick: inside box, juice spread thin and boil, sucking heat out of milk and meat. Now juice is warm gas full of stolen heat. Pump squeeze gas hard — squeezing make it hot, hotter than cave air. Hot gas run through pipes on back of box, cave air pull heat away, gas cool and turn back to liquid. Juice loop around, steal again, forever. Touch back of cold box — warm! That warm is yesterday's food heat. Cave wisdom: cold not thing you make. Cold just place where heat got carried away.