Drive Carefully

Dr. Christiaan Barnard (November 8, 1922 – September 2, 2001) was a South African heart surgeon who performed the world's first successful human-to-human heart transplant in 1967. The recipient, Louis Washkansky, lived for 18 days, a considerable milestone for the time.

This button implies that the doctor is waiting for organ donors and if you do not drive carefully you may become one.