A man from Surrey in England who installed a defibrillator on Everest at an altitude of 16,400ft (5,000m) has "shed tears of joy" after hearing it was used to save the life of a French female climber.
David Sullivan received the news via a phone call from a sherpa that the defibrillator had been used successfully. He told the BBC it made the climb to install it the "most amazing thing I've ever done".
