An eight-year-old boy had a youger sister who was dying of leukemia, and he was told that without a blood transfusion she would die. His parents explained to him that his blood was probably compatible with hers, and if so, he could be the blood doner. They asked him if they could test his blood. He said sure. So they did and it was a good match. Then they asked if he would give his sister a pint of blood, that it could be her only chance of living. He said he would have to think about it overnight.
The next day he went to his parents and said he was willing to donate the blood. So they took him to the hospital where he was put on a gurney beside his six-year-old sister. Both of them were hooked up to IVs. A nurse withdrew a pint of blood from the boy, which was then put in the girl's IV. The boy lay on his gurney in silence while the blood dripped into his sister, until the doctor came over to see how he was doing. Then the boy opened his eyes and asked, "How soon until I start to die?"