I was spoilt in college. They had changing boxes. Nice large things you could easily stack a 2-reel container, camera body, and all bits and pieces and still have space to move. Downgrading to a changing bag at home has killed me, pity morals stop me from theft!!!
I've got in the habit of working as careful as possible, but as fast as possible, to avoid spending long enough to get a humid atmosphere in the bag. It's awful when it gets sticky.