Eighteen-year-old senior-class president Connor Randall will walk across the stage at Ralston Valley High School’s graduation next month, accept his diploma, and head off to college. But just five years ago, Randall didn’t have enough strength to climb a flight of stairs. His body was rejecting his transplanted heart, an organ he’d received as an infant because he was born with cardiomyopathy (in his case, an abnormal heart). Doctors guessed that he had less than a week to live when he finally received a new heart in a transplant surgery that required at least three pints of donated blood.

Every two seconds someone—like Randall—in the United States needs a transfusion of donated blood for everything from cancer treatment to trauma surgeries. In fact, more than 90 percent of Americans will require a blood product transfusion in their lifetimes. In Colorado, most of that blood comes from the Bonfils Blood Center, which provides more than 80 percent of the state’s blood supply to nearly 200 hospitals and health-care facilities. The problem is the supply: Bonfils needs more than 3,300 volunteer donors each week in order to meet normal demand and build up stores for tragedies like 9/11.

To do so, Bonfils relies on dedicated volunteers, like 47-year-old marketing specialist Larry Cloos, who has donated more than 55 gallons of blood products since 1981. He has a standing appointment every Thursday to give plasma, the liquid portion of the blood that is used to treat patients with severe burns and clotting disorders. Donating just the platelet portion of his blood allows Cloos to donate more frequently, something he sees as being an invaluable gift. “It is all about time,” says Cloos. “The most precious resource any of us have is time.”

But Coloradans can still give more: Sixty-four percent of driver’s license or ID card applicants in Colorado register as organ and tissue donors, yet only four percent of the population donates blood. The lowering of the blood donation age last year—from 17 to 16 with parental consent—means more Coloradans are now able to donate blood for patients like Connor Randall, who testified in front of the state Senate last year, pleading for the passage of the age-lowering law. “I’ve seen the benefit firsthand in the hospital,” says Randall. “I’ve sat there with sickle-cell kids, the kids that depend on it. Kids like me.”