U.S. Air Force Staff Sgt. Kevin Matthews, 54th Air Refueling Squadron boom operator instructor, climbs over a hurdle during the Gut Check Challenge as part of National Police Week, May 14, 2014. The challenge consisted of events including hurdles, tire flips and self-aid and buddy care. Police Week is celebrated the week of May 15, which is Peace Officers Memorial Day. (U.S. Air Force photo by Airman 1st Class J. Zuriel Lee/Released)