I mean it, literally don't. Panic is just a waste of energy. Stay cool, stay calm, and stay hydrated. Trust us, we've been in tougher spots than you'll ever be.
A good shelter is like a good friend, it's where you want to be when the world is going to hell. Look for a nice cave, a sturdy tent, or a well-ventilated shed. Just make sure it's not a porta-potty.
Fire, fire, fire, everywhere! No, seriously, fire is not the best idea. A nice, bright yellow flare or a shiny mirror might be more effective. Just don't forget the Morse code, or you'll be stuck in a sea of confusion.