The cold air always takes some of the life out of your camera batteries. Try these tricks to extend the run time you will get out of your Alkaline, Lithium, Nickel Cadmium, NiMH (Nickel-Metal Hydride), or Lion (Lithium Ion) camera or flash batteries.
David Bergman’s tips in this video is to keep spare batteries in a pocket with activated chemical hand warmers while you’re shooting. And if you only have one battery, you can even tap a hand warmer to your camera to eek out some extra power.
I buy my hand warmers here on the cheap.