Cold temperatures kill batteries fast. You will find at colder temperatures they hold charge less well, but when warmed again the power will be registered. You can keep extra batteries in an inside pocket kept warm by your body heat. When the battery you are using starts to fade, change it for the nice warm one. - warming up the cold battery will restore it, and you can swap it when you need to.
It just means bring it below 0 degrees at your own risk! The contraction could adversely affect the chip etc inside the camera and shut down your camera once and for you~ You want can try to put it into the freezer to test it out and let us know? :sweatsm: