Blood is not like drinking water - you can't stockpile large supplies for use in emergencies. It has to be fairly fresh. And so the American Red Cross finds itself in its usual summertime bind of critically needing donations.
Red Cross Communications Manager Angie Bermudez says it's tough when 20 percent of blood drives take place on college campuses and at high schools.
She says with summer vacations, this is the time of greatest need.
"We're missing a large percentage of our regular donations," Bermudez says.