From the Canon Digital Learning Center Blog (post by Dan Carr):
"When winter rolls around, many landscapes go through dramatic changes that open up new possibilities for great photos. Snow-laden trees, icicles, frost patterns on foliage and winter sports are just a few of the many options. While many cameras are designed to work flawlessly at even down to 32 °F (0 °C), most will operate beyond this with a few simple precautions.If you take a camera into a cold environment, the first thing you might notice is that battery life begins to drop. By 32 °F (0 °C), you might only lose 10% of the battery’s potential, but if it grows colder then it starts to become more noticeable. The first step to combat this is to keep your spare batteries inside your clothing, as close to your body as possible. In moderately cold conditions, this will be more than enough to keep the batteries within a normal operating range. It might be tempting to keep smaller point-and-shoot cameras inside your layers as well, but even in cold temperatures, we sweat when exerting energy like when you’re walking through deep snow or skiing. This sweating will cause condensation on your lens and potentially inside your camera, so it’s best to keep smaller cameras in a backpack or outer pocket."
Check out the full article on the Canon Digital Learning Center Blog.