The doctor credited with inventing the mouth-to-mouth resuscitation technique known as the "kiss-of-life", has died in the United States aged 79.
Emergency resuscitation saves many lives around the world
The American Heart Association (AHA) confirmed Dr Peter Safar had died on Sunday, but did not give a cause of death.
The doctor - whose pioneering efforts have saved countless lives - was born in Austria in the 1920s and survived a Nazi labour camp before emigrating to the US after the war.
There are ancient references to the apparent use of mouth-to-mouth resuscitation in the Bible, but the technique fell out of practice until rediscovered by Dr Safar in the 1950s.
Also credited with playing a key role was his colleague, Dr James Elam.
Dr Safar's "kiss-of-life" was combined in the 1960s with new chest compressions to give us the technique we know today as CPR - cardio-pulmonary resuscitation.
The BBC's David Bamford in Washington says that before Safar's breakthroughs many dubious methods were used to try to revive people.
These included using hot ashes to shock the body back to life, flagellation, rolling victims down a hill in a barrel or tying them to a trotting horse.
Dr Safar helped create the organisation that would become the World Association for Disaster and Emergency Medicine in 1976.
He lived near Pittsburgh, Pennsylvania, and was a professor at the University of Pittsburgh medical school.
"Dr Safar's pioneering efforts and accomplishments in emergency and critical care medicine... have saved countless lives and gained international recognition," the AHA said in a statement.