ChiliPad keeps your mattress hot, cold - Engadget
http://www.engadget.com/2007/12/21/chilipad-keeps-your-mattress-hot-cold
"If Chili is to be believed, this thing can be set to cool things down to 65°F or warm 'em up to 100°F, and yes, it does come in single- and dual-zone versions."