A campaigner who climbed Mount Everest to install a defibrillator has revealed the device saved a woman's life - just three weeks later.

David Sullivan founded Code Blue CPR, an organisation which aims to teach people life-saving CPR and install more defibrillators across England, after he lost four close friends - all under the age of 45 - to cardiac arrest.

Mr Sullivan, 62, has spent the last several years travelling around the world trying to improve cardiac survival rates - and earlier this year ventured to the Himalayas, where he installed what he says is the world's highest defibrillator.

The dad-of-four, from Oxted, Surrey, first climbed to an altitude of 22,000 feet to test the defibrillator - and then descended to one of the villages near Everest Base Camp, at just over 16,500 feet, to install the device for use.

He returned from Everest on April 30 - and, just three weeks after, learnt that the defibrillator had saved a climber's life when her heart stopped.

Mr Sullivan said: "It was the proudest moment of my life when I learnt what had happened. "

"It was last Friday (May 23), at around 3:45am. I have kids travelling the world so I initially thought, 'oh my God, something's happened'. "

"But it was a sherpa [an Everest guide] who told me the defibrillator had been activated and had saved a 30-year-old French woman's life. "

"It is incredible that something so simple can save someone's life - and I hope it will help people realise how important it is to have access to defibrillators. "

"Being within three minutes of a defibrillator increases your chance of survival from 8 per cent to more than 50 percent."

While Mr Sullivan was in Nepal, he also gave multiple CPR and defibrillator classes to Sherpas and locals - who had had no previous access to the training.

Now that he's back in the UK, Mr Sullivan is preparing to present a training programme to the government - which would see 1.2 million children across London trained in CPR.

He said: "The teaching of CPR in the UK is disgraceful. I have travelled the world to cities where cardiac arrest survival rates reach over 57 per cent - and in the UK, the rate is eight per cent. "

"We want every school to have a new defibrillator and every person in the school - students, teachers, staff - to have all the training necessary to save someone's life. "

"We won't stop until we achieve that." "

Mr Sullivan knows himself how valuable CPR training can be - as he saved a young golfer's life just three months after he completed a course.

He said: "I performed nine minutes of CPR for a young lad and used a defibrillator just three months after I had been shown how to. "

"While I was doing this, around 30 people just watched and didn't help - because they didn't know how. "

"When the lad's mum called me the next day to say he was alive, it changed my life forever."

"I knew then that everyone should know how to save a life."

To find out more about Mr Sullivan's work, visit the Code Blue CPR website: https://codebluecpr.co/contact/