A U.S. Air Force Airman gets his vital signs checked prior to donning a hazardous material suit during a chemical, biological, radiological, nuclear and high-yield explosive threat exercise at Langley Air Force Base, Va., March 26, 2015. During the exercise, participants created a contamination control center, implemented an incident scene control and provided logistical and administrative support. (U.S. Air Force photo by Senior Airman Kayla Newman/Released)