"As a tip, let me suggest your change cards before you come inside. Then you can do what you want with your filled card, and not be tempted to open the bag. When coming in from freezing temperatures, I usually plan on an hour for the camera to warm up."

Thanks guys - interesting thread. I am wondering about the hour for the warm-up...seems a bit long to me. Shooting weddings, I am constantly going from cold to warm and vice versa in the winter. While I realize it is NOT exactly the same due to the amounts of time I am actually outside, I am trying to figure out the conditions that would require an hour for warm up (and please pardon that one if it sounds stupid).

Cheers
James