Environmental control
BALAD AIR BASE, Iraq -- Airman 1st Class Brandon Bolden, a 332nd Expeditionary Civil Engineer Squadron heating, ventilation and air conditioning technician, charges an environmental control unit with refrigerant here, Jan. 10. The refrigerant prevents the unit from over heating. Airman Bolden is deployed from Ellsworth Air Force Base, S.D. (U.S. Air Force photo/Staff Sgt. Joshua Garcia)