Most powder manufactures reccomend that powders may break down faster if stored in such high outside temperatures, but the cold of winter will not bother them. I have even heard of some shooters keeping there powder in a frige for longevity. Guess I'm lucky, none of mine seems to last long enough to go bad! Interesting subject. Never thought of temp. extremes to loading cartriges beyond outside temp. "while" shooting as regards to hot loads.