Operational Readiness Exercise
Airman 1st Class Ryan Wymer, 15th Aircraft Maintenance Squadron, takes a drink from his canteen while in mission-oriented protective posture four during an Operational Readiness Exercise at Joint Base Pearl Harbor-Hickam, Hawaii, July 18, 2013. Much like standardized attack warning signals, MOPP quickly increases or decreases Airmen’s protection against chemical, biological, radiological or nuclear threats. (U.S. Air Force photo/Tech. Sgt. Jerome S. Tayborn)