Bag-valve masks (BMVs) have an oxygen mask which covers the nose and mouth of the patient, a one-way valve attached between the mask and the bag which filters the moving air and prevents the air to be breathed back into the bag, and an inflatable bag which holds the air in and is squeezed by hand. An operator squeezes the bag which forces air into the patient's lungs, and as the hand releases the bag is the patient breathes out into the outer environment and the bag refills itself with outside air. The bag is squeezed and released by hand repeatedly in order to keep the patient breathing.