Another thought that might help with this John, Lee Carmichael (lee here on APUG) and AllenR got me to using the large ziplock bag (have 4x5, 5x7 and 8x10). In the situation you described, the bag would have had condensation on it, but if left out to come to temp. the holder/film would have been fine. Just a thought and they also work great for keeping dust out. Plus, take notes for each shot on an index card, drop into the bag and don't have to worry about a notebook or anything in the field.