There have been many ways how a phone could come to rescue in an emergency. But if you don't have time to do anything, this iPhone 5 whistle case could come in handy.

The case is called Hoo, and it is a loud whistle that is built into its outer shell with a mouthpiece hanging off the top. Easy to use and works even if your iPhone runs out of battery. Plus it'll protect your phone. Whoopie! Get it at Whistle Case.