EMERGENCY services battled for more than four hours overnight to reach a couple poisoned by carbon monoxide.
John Lightfoot, 84, and his wife Beryl, 79, were found collapsed at their remote home on the Horseshoe Pass in Llangollen.
Their son, Gwyn, came down the stairs to find his parents had passed out on the floor on Saturday.
Exhaust fumes from a power generator engulfed the ground floor after a snow drift blocked the vents.
The family had to switch the generator on after their main electricity supply was cut off by the bad weather.
Mr Lightfoot called the emergency services at 10pm, but due to snow drifts of up to seven foot it took mountain rescue teams from North East Wales Search and Rescue (NEWSAR) until 2.30am to reach them.
An ambulance which was called to the scene was unable to make it all the way, so the six rescue workers and their doctor were towed by a tractor driver from Tomlinsons Dairies to get them to the farm.
After they were rescued the tractor helped the Lightfoots to a safe clearing to be picked up by the ambulance service.
“I came down stairs and opened all the windows, I didn’t realise that carbon monoxide was really such a silent killer, it came really fast,” said Mr Lightfoot.
“The snow drift had blown and blocked the vents,” he added.
Carbon monoxide poisoning can be caused during winter in an unventilated area where a vent to a fuel-burning appliance becomes covered with snow.
The gas cannot be seen or smelt and people can become unconscious without realising.
“The mountain rescue team came out to the house, they did a fantastic job,” said Mr Lightfoot.
“It took them four hours to get here, but they were great under the circumstances.
“The ambulance had to wait at the roundabout, one mile away,” he added.
Tomlinsons Dairies helped get Mr and Mrs Lightfoot down to the ambulance with their tractor.
“Tomlinsons Dairies helped a lot, they were great, a big thank you to them,” said Mr Lightfoot.
“People do not realise how bad we get the snow where we are.
“But all the emergency services helped so much,” he added.
Iain Ashcroft, team leader at NEWSAR said: “It was one of 22 calls we had in less than 48 hours.
“We got called in by the ambulance service to get the people, because the ambulance couldn’t get up there.
“We had to be towed by tractor to get our team vehicle and our doctor to the location.
“The couple were then transported to a clearing which the ambulance could reach.
“We had two vehicles involved and six NEWSAR team members.”
The ambulance took Mr and Mrs Lightfoot to Wrexham Maelor and they are now recovering at their daughter’s house in Brymbo.
A North Wales Fire and Rescue Service spokesman issued advice on how to prevent carbon monoxide poisoning.
They said: “We strongly recommend the use of audible carbon monoxide (CO) alarms.
“Before buying a CO alarm, always ensure it complies with British Standard EN 50291 and carries a British or European approval mark, such as a Kitemark.
“CO alarms should be installed, checked and serviced in line with the manufacturer’s instructions.”