Cold kills the batteries in a hurry..........like reelcrazyfish said tape handwarmers over the bat. on the camera and the spares should be kept inside your jacket close to you for body warmth............Video in the cold isn't bad for your equip. just be sure and get some long life batteries and keep them warm............also remember at the end of the day you should not take your camera from the cold directly to a warm house or camp, it will cause condensation inside the camera.