U.S. Air Force Staff Sgt. Mathew Eaves supervises fellow airmen as they transition from Mopp 2 to Mopp 4 during CBRNE survival skills training on the Mississippi Combat Readiness Training Center, Gulfport, Miss., June 18, 2014. Eaves instructed airmen on the proper use and wear of the chemical suit. (U.S. Air Force photo by Senior Airman Jessica Fielder/Released)