Final answer:
After calling for help, the first thing to do is to check for breathing and pulse, and if necessary, start CPR before using an AED.
Step-by-step explanation:
Upon arriving at a scene where a person has collapsed and is unresponsive, after calling for help, you should immediately check for breathing and a pulse. If the individual is not breathing or does not have a pulse, CPR (cardiopulmonary resuscitation) should be initiated before using an Automated External Defibrillator (AED).
While AEDs are crucial in diagnosing and applying a therapeutic shock in cases of cardiac arrhythmias, CPR is recommended to support circulation and oxygenation until the AED is ready to be used or further medical help arrives. After checking for a response and not receiving one, they should check if the person is breathing and has a pulse. If the person is not breathing or does not have a pulse, the student should immediately begin CPR.