High Heat
130717-Z-VA767-003 -- Airman 1st Class Brandon Reif takes a series of temperature readings at Selfridge Air National Guard Base, Mich., on July 17, 2013. The temperatures that day approached 90 degrees, the implementation point for a number of heat-related work/rest cycle precautions. (U.S. Air National Guard photo by TSgt. Dan Heaton / Released)