What should you do if a person is unresponsive and not breathing?

When encountering a situation where a person is unresponsive and not breathing, the first and most critical action is to call emergency services and initiate Cardiopulmonary Resuscitation (CPR). This response is vital because it helps maintain blood circulation and oxygenation to vital organs, particularly the brain, until professional medical help arrives. Time is of the essence in such emergencies, and starting CPR immediately can significantly increase the chances of survival.

Calling emergency services alerts trained responders who can provide advanced care, while administering CPR helps sustain the life of the individual after they've ceased to breathe. This proactive approach is a crucial step in the chain of survival for cardiac arrest and unresponsiveness situations.

Other options, such as checking for a pulse or shaking the person, do not provide immediate assistance and may waste precious time. Only performing rescue breaths without CPR is insufficient because it does not address the absence of circulation. Hence, the best course of action is the combination of calling for help and starting CPR, ensuring the person receives the immediate aid they need.