I don't have and have never had the luxury of a warm place to keep all of my crap, er, tackle. I make sure that the rods are stored upright and STRAIGHT. This year I'll be pulling all of my reels off for cleaning, so they'll be warm, at least for a while.
I've had most of my bait problems (hard baits) in extreme hot weather. The heat causes the glue in them to go to a semi-gaseous state, and they get fat. Not good fat, either.