Survival Tip #1: Stay calm.
It is far too easy to make a bad situation worse when not thinking clearly.
Take a minute to sit and think. Consider your options. If you are unsure as to what should be done next, then don't do anything.
Count to 30.
It will seem like an eternity, though in reality will only take you about 10-15 seconds. In that time your body will stop producing adrenaline and you can start the calming process.
This is always the first step in any emergency situation.