Kelsey Mathison draws a unit of blood using the Haemonetics machine which allows the donor to give a double unit of red blood cells. The Inland Northwest Blood Center parked the parking lot of the Exchange, Fairchild Air Force Base, Wash., Jan. 25, 2013. The advantage of donating a double unit of red blood cells is that it lessens any reactions with the donor and the recipient. (US Air Force Photo by Senior Airman Jordan Pollock)