Participants in the Air Force Research Laboratory 2015 Tech Warrior exercise exit an abandoned building Sept. 15, 2015, after a smoke grenade simulating mustard gas was released during their search for a weapons cache as part of a dismounted patrol scenario. During the exercise, held at the National Center for Medical Readiness in Fairborn, Ohio, participants learned a variety of skills such as base defense, self-aid buddy care, tactical vehicle driving and land navigation. (U.S. Air Force photo/Bryan Ripple)