During cold weather, make sure you have at least one Ziploc bag in your camera case. Not only are they useful for protecting your equipment in the rain, but they help with condensation too.
Bringing a camera in from the cold weather to a warm house promotes condensation forming on the outside of its body, possibly migrating to the inside of the camera where it can confound electrical components. To prevent this mishap, place your camera in a Ziploc bag before coming inside. Leave the camera in the sealed bag until it reaches room temperature. The condensation will collect on the bag, not your camera, thereby protecting your investment.