When you are alone and have to perform cardiopulmonary resuscitation (CPR), your primary effort should be compressing the chest to help the person's heart pump blood. If there is a second person helping, providing breaths can be done at the same time as compressions are performed.
The brief review of CPR on the following pages can help you in an emergency; however, this information should not take the place of a certified course in CPR.
Assess the situation. Call out for someone to get help or call 911 yourself if the person does not seem to need immediate assistance. You can determine this by gently shaking the person and asking in a loud voice, "Are you OK?" If there is no response, begin CPR and continue until help arrives.