Capt. Jessica L. Switzer, 319th Mission Support Group executive officer, checks a manikin for breathing during a cardiopulmonary resuscitation training class Oct. 6 at the Medical Treatment Facility on Grand Forks Air Force Base, N.D. CPR is a combination of rescue breathing and chest compressions delivered to victims thought to be in cardiac arrest. When cardiac arrest occurs, the heart stops pumping blood. CPR can support a small amount of blood flow to the heart and brain to “buy time” until normal heart function is restored. (U.S. Air Force photo by Senior Airman R. Michael Longoria)