By Owain Clarke
A year ago, Andrew Barnett collapsed and his heart stopped beating, as he played football with his young son.
Luckily, it was at on a pitch at a Cardiff leisure centre - which had a defibrillator - and the manager knew CPR techniques.
Andrew, 46, was revived and became part of a hospital trial to see if cooling the body in intensive care helps recovery.
The event was a complete blank but he realises how close to death he came.
The cooling trial, involving nine UK hospitals, is being led by researchers at the University Hospital of Wales, Cardiff.
Altogether, 1,900 patients worldwide are part of the trial, called TTM2.
Half of patients were cooled down, often with pads and cold water, to bring them down to a temperature of 33C - our normal body temperature is 37.5C. They're kept like that for 24 hours, as well as getting all the usual life-saving treatment.
The other half are kept at normal temperature - but not allowed to get hot either - so the results can eventually be compared.
Dr Matt Morgan, intensive care consultant and researcher, is one of those leading the trial.
"It is looking at the importance of protecting the brain after someone suffers a cardiac arrest - and there have been theories since the 1960s of cooling the body to help protect the brain," said Dr Morgan.
"It's been used quite extensively in intensive care worldwide but what we really don't know is if that's truly beneficial."
'I couldn't believe it'
It was a during a "fathers and sons" football match the week before Christmas, with his seven-year-old son Seb, that Andrew collapsed.
He led an active lifestyle and works for a sportswear company but did not know that he had a blocked artery.
"It was a usual day," he recalled, ahead of the game on Astroturf at Eastern Leisure Centre in Llanrumney.
"I'd worked from home and been for a swim at lunchtime and brought my son up for the game in the evening. I have very little recollection, only what I've been told by the people who were there.
"I don't remember the game at all or falling over. They grouped around me to see what was wrong but I was completely out so they knew it was something serious."
Ben Clarke, leisure centre duty manager, was in the office when he was told about Andrew's collapse.
"I grabbed the defibrillator from reception and ran out - as soon as I got there I could see he was not in a good way, he was unconscious," he said.
"I knew he'd gone - his heart had stopped. I started CPR - a colleague started unpacking the defib. I did four or five cycles of CPR and the machine showed he needed a shock. He was a grey-blue colour and it was clear he was 'dead'".
The defibrillator also indicated he needed two more cycles of CPR - and Ben did this until Andrew started to show signs of life and the ambulance arrived.
When Andrew was admitted to the University Hospital of Wales, he was sedated and included in the trial - until he was taken off both the following day.
He cannot remember anything that happened the previous week - only waking up in the critical care unit the following morning.
"The first recollection I had was when they told me I'd had a cardiac arrest - I looked at the wall and I couldn't believe it, it was the sort of thing that happened to someone else."
About 6,000 people in Wales need resuscitating outside hospitals every year but only about 10% of these patients ever recover and leave hospital. Andrew is one of the lucky ones.
For Ben, it emphasised the importance of defibrillators being available in public places.
"It was good to know you'd helped save someone," he said. "Me and Andrew have met up a couple of times for a drink - we've formed a friendship out of something which was negative."