Using a medical mannequin, an #Army combat medic teaches an #Airman to perform a chest needle decompression to treat a chest wound injury July 7, 2011, during a tactical field care exercise at Contingency Operating Site Marez, #Iraq. (U.S. Army photo/Spc. Terence Ewings)

Using a medical mannequin, an #Army combat medic teaches an #Airman to perform a chest needle decompression to treat a chest wound injury July 7, 2011, during a tactical field care exercise at Contingency Operating Site Marez, #Iraq. (U.S. Army photo/Spc. Terence Ewings)