What is the first action to take when encountering an unconscious person?

The first step when encountering an unconscious person is to check for breathing. This involves looking, listening, and feeling for signs that the person is breathing. If the person is not breathing, it indicates that they may be in a critical situation and may require immediate intervention, such as calling for help and potentially performing CPR.

Checking for pulse is also an important step, but it follows ensuring the person is breathing or not. Similarly, calling 911 is crucial, but it typically occurs after assessing the person's condition. Performing CPR would be warranted if it is determined that the person is not breathing. Thus, checking for breathing is a vital priority in this scenario.