U.S. Air Force Staff Sgts. Will Davey and Chris Rundell, Heating Ventilation and Air Conditioning (HVAC) craftsmen assigned to the 633rd Civil Engineer Squadron, gain access to a maintenance room at Langley Air Force Base, Va., Jan. 5, 2016. Davey and Rendell fixed an HVAC system, ensuring personnel had heat to perform their mission in a comfortable environment. (U.S. Air Force by Staff Sgt. J.D. Strong II)