What is the first step to take with a casualty who is unconscious and not breathing?

When encountering a casualty who is unconscious and not breathing, the first step is to check for danger. This is crucial because ensuring the safety of both the rescuer and the casualty is paramount before any further actions can be taken. If the environment is unsafe, such as in the presence of fire, electrical hazards, or moving traffic, moving the casualty or performing further interventions could result in additional harm.

By assessing the situation for any potential dangers, the responder can determine whether it is safe to approach the casualty and provide assistance. Once safety is established, the responder can then proceed to call for help, check for responsiveness, and initiate necessary life-saving measures such as chest compressions or rescue breathing if appropriate. This foundational step of checking for danger ultimately helps ensure that rescuers can effectively respond without putting themselves or others at further risk.