As winter has a firm grip on Canada, so does the cold!! Even though it's chilly out, it doesn't mean we can't take our cameras out into the elements to get those great winter shots, but it does mean we have to be a bit more careful while doing it.
Most camera makers give an operating temperature of between 32° to 104° Fahrenheit (0° to 40° Celsius), the cameras should operate as designed with out any problems, and they will. I have used mine down to -10 degrees with no issues what so ever. It's when you get a camera and lens this cold and then bring it into a warmer environment that you can have problems.
Condensation can build up very quickly inside a lens and camera body that goes from cold to warm. So what do you do?? You have to let the camera and lens gradually warm back up to room temperature, and this can easily be done by placing the camera and lens into a large plastic bag and sealing it off. From there I usually put the whole combo back into my camera bag and zip it up. This allows for a very slow acclimatization back to normal temps and prevents any condensation from developing in side the lens or body.
Another problem that can occur in cold weather shooting, is battery life. Batteries can fail to operate when they get really cold, so it is always a good idea to keep them as warm as possible. One way to do this is to keep them in your pocket, switching them back and forth as needed from pocket to camera. If using an SLR, I recommend a battery grip that holds two batteries, as this does help supply more power to the camera when things get a bit cold.
Lastly get out there and enjoy the winter!! Knowing how to handle your gear in the cold will allow you to take those great shots all season long!!