Staff Sgt. Joshua Cox prepares to donate blood at the American Red Cross Blood Drive held at the Fitness and Sports Center on Joint Base Charleston, S.C., April 21, 2010. This is the third blood drive the Red Cross has held at Joint Base Charleston this year. The Red Cross estimated to have more than 100 donators by the end of the day. Sergeant Cox is a military training leader with the 373rd Training Squadron. (U.S. Air Force Photo/Airman 1st Class Lauren Main)

Staff Sgt. Joshua Cox sits patiently as he donates blood during the Red Cross Blood Drive held at the Fitness and Sports Center on Joint Base Charleston, S.C., April 21, 2010. O-Negative blood type is the most needed blood because everyone can receive it. The blood donated at Joint Base Charleston is distributed to hospitals around South Carolina. Sergeant Cox is a military training leader with the 373rd Training Squadron. (U.S. Air Force Photo/Airman 1st Class Lauren Main)

Members of Joint Team Charleston wait in line at the Fitness and Sports Center to donate blood at the Red Cross Blood Drive on Joint Base Charleston, S.C., April 21, 2010. The Red Cross hoped to receive at least 91 donations today to distribute to hospitals around South Carolina. The average shelf life of blood is 41 days. Due to the major surgeries conducted at the Medical University of South Carolina, the blood is always used and never thrown away. Often times there is a shortage and blood must be imported from other states. (U.S. Air Force Photo/Airman 1st Class Lauren Main)

2nd Lieutenant Susan Carlson prepares to donate blood at the Red Cross Blood Drive held at the Fitness and Sports Center on Joint Base Charleston, S.C., April 21, 2010. This is the third Red Cross blood drive held on Joint Base Charleston this year. The local Red Cross goes as far north as Myrtle Beach, S.C., and as far south as Walterboro, S.C., to collect donations. Lieutenant Carlson is a Public Affairs officer with the 628th Air Base Wing. (U.S. Air Force Photo/Airman 1st Class Lauren Main)