How to Keep Your iPhone From "Bricking" in Cold Weather (MentalFloss.com)

You’ve just built the perfect snowman: top hat, carrot nose, corncob pipe, the works. You whip your iPhone out to snap a photo for your Instagram feed, but the screen won't come on. It was fully charged when you left the house, so what happened? Did the cold weather kill your phone?

http://mentalfloss.com/article/518365/how-keep-your-iphone-bricking-cold-weather