GCroyle... . insulation is all about interrupting the transfer of heat from a warm place to a cold place. Your beer is supposed to be a cold place. You want to keep environmental heat out of that cold place, so you insulate it with a "koozie", or an ice-chest, or some towels wrapped around it. The insulation (towel, ice-chest or koozie) cannot discriminate between your beer and your baked potatoes. It just slows down (never actually halts) the movement of heat. That other thingie is a really neat thermo-electric deal that either generates heat when the 12VDC runs thru it in one direction, or it absorbs heat (gets cold) when you reverse the polarity. We used to have one. They're not super-efficient. They'll drain a car or boat battery if the engine's not running pretty quick. It seems like their limit is, like 30 or 40*F above or below ambient temperature. Your "hot" food needs to go in hot, and it'll keep in warm longer than a plain ice-chest. Your cold food needs to go in cold, and you just won't have to buy as much ice.