I have no idea of what some of you are talking about. I live in the interior of Alaska where it gets very cold. I just go out there and take pictures, sometimes 20 minutes at a time, run back to my truck to warm-up for ten minutes, and then back out to take more pictures. However, on a cold day your breath can reach the filter or lens' glass, and the condensation may freeze on it. Not inside the lens. However, when I say "cold" I mean cold (like -45 degrees F) If it's around 40 degrees where you shoot, then it's possible for some condensation to develop inside the camera. At -45 the air is very dry.
I place a couple of hand warmers in the pack next to the camera. A battery's capacity is reduced quite a lot when very cold, and the hand warmers keep the camera and battery a few degrees warmer than ambient temperatures.
Now, if you use your camera in a very humid place, or in the rain, moisture could very well get inside and condensate.