D.R. has it written on the sheet inside his survival kit. In case you get get lost, STOP. STOP, THINK, OBSERVE, PLAN. Or, sit down and make a cup of tea. Whatever works for you. The point is to slow your though process down and get focused on a task so you don't fall into panic mode.

I'm sure there are methods for general panic attacks as well such as focusing on breathing, counting to 10, etc. You want to put your mind to work, not let it run wild.