I do not wish this on anyone, but dropping your iPhone in some sort of water is always a possibility. I have never done this (knock on wood), but what do you do if your iPhone inadvertently ends up in some type of water? It turns out there is quite an extensive procedure for dealing with a submerged iOS device. This articles lists all the things you can do to hopefully fix an iPhone that has been submerged into some sort of water. The article also lists several things your should NOT do to recover your iPhone.