Hi Susan,
I work in color and do not use fiber base photo papers that are dry mounted. I do archivally mount Fuji Crystal Archive photos most of which are framed in wood. These are even stored in my trailer (which is stored in my garage between Art Shows) in all kinds of weather. The photos do adjust due to the humidity (including rain) and temperature. For my work, I am more concerned about the heat than the cold and that includes shipping orders left in FEDEX or DHL trucks in the heat. However, for all dry mounted images, the photo paper is under much more stress due to expansion, contraction, and flexing of the backing board, adhesive, and the photo paper itself.
Rich