Check the scene for safety, form an initial impression, and use personal protective equipment (PPE) if available.

Call 9-1-1 or ask someone to do so

Open the victim’s airway and check for obstructions like food or vomit. 

Check for breathing by placing your ear next to the victim's mouth and listen for 10 seconds. 

Perform chest compressions. CPR guidelines recommend 100 to 120 chest compressions per minute, 30 at a time.

Give two rescue breaths. Open the airway using the head-tilt/chin-lift technique. Pinch the nose shut, take a normal breath, and make complete seal over the person’s mouth with your mouth. Ensure each breath lasts about one second and makes the chest rise.

Continue giving sets of 30 chest compressions and 2 breaths until medical help arrives.