Airman First Class William Raetz, 341st Medical Operations Squadron, collects air quality samples during a local emergency response exercise held at Malmstrom Air Force Base, Mont. Oct. 27, 2014 as part of Global Thunder 15. Raetz is part of the Chemical, Biological, Radiological and Nuclear Emergency Response Force, or CERF, who are an integrated team combining the skillsets of emergency management and bioenvironmental flights. Global Thunder is a U.S. Strategic Command annual field training and battle staff exercise designed to exercise all mission areas with primary emphasis on nuclear command, control and communications. This field training and battle staff exercise provides training opportunities for components, task forces, units, and command posts to deter and, if necessary, defeat a military attack against the United States and to employ forces as directed by the president. (U.S. Air Force photo/Christy Mason)