I read the article on Heat Stress and it got me thinking. I live in far northern Minnesota and heat isn't quite the problem here that it is in southern states. Has anyone looked into the detrimental effects that extreme cold might have on instruments? If I'm storing a guitar or other stringed instrument out where it'll get much below freezing (it can get below -40 here), I loosen the strings in case the cold might shrink and break them (or the neck). Is this a reasonable practice or what?