Colder than ice
Staff Sgt. Joseph Olejniczak, (right) 4th Logistic Readiness Squadron terminal operations technician, shows Airman 1st Class Michael Tipton, 4th LRS distribution technician, how to purge a liquid oxygen line before filling a container for transport on Seymour Johnson Air Force Base, N.C., Jan. 5, 2010. Liquid oxygen is used in aircraft during in-flight emergencies when the cabin loses pressure, so the aircrew can breathe. Sergeant Olejniczak hails from Santa Fe, Tenn., and Airman Tipton hails from El Paso, Texas. (U.S. Air Force photo/Airman 1st Class Rae Perry)