It's very cold here in Anchorage, Alaska also. It's "warmed" up to 20 degrees today (-8 Celsius). Right now it is snowing like crazy.

What we use is a product called Snuggle Safe Heat Pads. You put it in the microwave for a few minutes and it stays warm for 12 hours. It really works.
http://www.petsmart.com/products/product_12125.shtml