Uncle Martin was startled. He quickly called for help and helped the doctors bring Barrett to a bed in the ward. Meanwhile, he sternly asked the nurse, "How much blood did you draw in one go?"

The nurse who had drawn the blood hurried over, looking flustered.

"We drew... we drew 600 milliliters," she stammered. "There was no Rh-negative blood left in the hospital, and this gentleman insisted he was fine, and the emergency room urgently needed blood, so I drew a bit more."

Normally, when Barrett had donated 400 milliliters, he should have shown obvious signs of discomfort.

But he kept saying he felt perfectly fine.

The duty chief...