Pause. Do not act on the impulse. Say "stop" out loud.
In for 4, hold for 4, out for 6. Repeat three times.
Am I safe right now? What triggered this? Name the feeling.
Fact or feeling? What would a trusted friend say right now?
Best action right now? Call someone. Regulate. Walk away from the phone.
When the wave is loud and the body will not settle, you do not have to ride it alone. Continue with the Nervous System Check-In to find your way back to steady.