There's been a lot of mention of transparency film. I suppose old stock might be shot, but these days, transparency means Fuji. Fuji have the best film data sheets in the business. If you check these, they will advise you that unprocessed, exposed, or unexposed film is best stored below 0C prior to development, if there will be any delay in processing. Don't take my word for it: google up the sheets, Fuji will have them on their website. As the manufacturer, they ought to know, and that is all I need to know, personally, and it is good enough for me.