CPR is one of those things that most people conceptually know how to do, but when faced with a crucial moment where they actually have to perform, the details get a little fuzzy.
According to the American Heart Association, there are only two things that actually need to occur when someone collapses. First and foremost, someone should call 911 - this step needs to occur before anything else, even if your first instinct is to help the afflicted person. Once an ambulance is on its way, it's time to take matters in your own hands and perform CPR at 100 beats per minute.
But what, exactly, is 100 bpm? What does that sound like? This clever video gives you a simple trick to remember - and it's actually pretty awesome.
Next, this video can help you save yourself from choking.