U.S. Air Force Capt. Marie Carillo, 79th Fighter Squadron assistant director of operations, prepares to initiate the artificial hypoxic environment using the reduced oxygen breathing device (ROBD) at Shaw Air Force Base, South Carolina, Oct. 15, 2021. The aerospace physiology refresher course trains on the ROBD operations which creates a real-time hypoxic environment for pilots to recognize their symptoms and utilize aircraft systems to correct and declare an emergency. (U.S. Air Force photo by Tech. Sgt. Isaac D. Garden)