U.S. Air Force and Royal Australian Air Force humanitarian assistance/disaster relief (HA/DR) personnel set up an ac unit during exercise COPE NORTH 2018 at Rota, U.S. Commonwealth of the Northern Mariana Islands, Feb. 17. An annual exercise, this year's COPE NORTH is a multilateral HA/DR exercise that allows participating nations to prepare for and recover from the devastating effects of natural disasters. (U.S. Air Force photo by Airman 1st Class Christopher Quail)