U.S. Marines with Headquarters and Service Company, Combat Logistics Regiment 17 (CLR-17), 1st Marine Logistics Group, conduct a Chemical Biological Radiation Nuclear (CBRN) conditioning course on Marine Corps Base Camp Pendleton, Calif., April 18, 2013. CLR-17 Marines condition themselves through team building exercises in full protective gear under stressful conditions flipping a tractor tire to prepare themselves for actual emergency situations. (U.S. Marine Corps Imagery by Lance Cpl. Alexander Quiles 1st MLG Combat Camera/Released)