The First Aid of a medical emergency is as follows: Airway: Check the airway for obstructions. Breathing: After confirming that the airways are clear, determine whether the person is able to breathe. Circulation: If the person does not breathe, the First Aid renderer should immediately begin with CPR, which involves chest compressions and rescue breathing. Deadly bleeding or defibrillation: Treating severe wounds or performing defibrillation on the heart.