Oh My! I Think I Found It!

[rjgimp]

Some 26 odd (very odd) years ago when I started out in trucking I bought a 12vdc Coleman cooler for around $100. It still functions well to this day. It contains a heat sink and a small fan. It does only cool to about 30 or so degrees below ambient which is outstanding for drinks on a hot day but is indeed nearly worthless for protecting perishables from spoiling over time. The nifty thing I quickly discovered about this unit is that it has a polarity switch which reverses the direction of the heat sink and fan and turns the unit into a small warming oven of sorts. No actual baking going on by any means but I can put a plate of leftovers in there and two hours down the road it's hot enough to burn your tongue!