Generate a simple, clear guide on how to help someone who is having a panic attack. Use a 'Do This, Not That' format. 'Do's' should include staying calm, speaking in short sentences, and asking them what they need. 'Don'ts' should include telling them to 'calm down,' dismissing their fear, or crowding them. The tone should be direct and helpful. Please include a disclaimer about not being a substitute for professional emergency help.