When Tom Fisher had a heart attack on an isolated island in the Bahamas, he was relieved to have Dr Dan Carlin on call. Carlin talked Fisher’s companions through performing cardiopulmonary resuscitation and using the defibrillator he had provided. Together, they were able to revive him.

“There was an on-island nurse on the phone telling me he had been dead for 30 or 35 seconds,” Carlin recalls. “It was like Lazarus.”