U.S. Air Force trainees cross a cold water pool during the basic training obstacle course on Lackland Air Force Base, Texas, June 30, 2010. The trainees are assigned to the 320th Training Squadron. U.S. Air Force trainees cross a cold water pool during the basic training obstacle course on Lackland Air Force Base, Texas, June 30, 2010. The trainees are assigned to the 320th Training Squadron. SHARE: Download: Full Size (3.28 MB) Tags: Photo Essays Credit: VIRIN: 094736-Q-TPN49-529.jpg Photo Gallery