The document provides guidance on performing adult basic life support (BLS). It explains that when someone experiences cardiac arrest, it is crucial to take swift action by starting chest compressions and rescue breathing without any equipment in order to restore oxygenated blood flow to the brain and heart. The key steps of BLS are to check for responsiveness, call for help, open the airway, check for breathing, and begin chest compressions combined with rescue breaths at a ratio of 30 compressions to 2 breaths. An automated external defibrillator may also be used if available to attempt to restore a normal heart rhythm through defibrillation. BLS should continue until qualified help arrives, the victim starts breathing on their own, or the resc