A Radlett couple were minutes away from death as they slept while a blaze took hold in their lounge caused by an electrical fault in a television that was only three years old.

John and Heather Hookway's lives were saved by the smoke alarm which woke them up, and alerted them to the toxic fumes that could have suffocated them in their sleep.

The block of flats in The Dell had to be evacuated and the couple, and three neighbours, were treated in hospital for smoke inhalation.

John and Heather were watching television before going to bed at around 11pm and leaving the set on stand-by.

At 1.50am last Thursday, they woke as the alarm sounded and smoke started to fill their ground-floor flat.

John, 27, tried unsuccessfully to extinguish the fire while 25-year-old Heather called the fire brigade.

John, a youth worker at St Johns Church and Christ Church in Radlett, then raced around the block of flats alerting neighbours, in smoke that was so thick he needed a torch and could not see more than five inches ahead.

He said: "I was breathing in black, thick, plastic smoke it felt horrible and I was choking. I was just thinking for their safety and to get them out.

"I knew each breath I took my lungs were filling up with gunk and this black stuff."

When he came outside John collapsed and was given oxygen by firefighters who had arrived from Radlett, Borehamwood and Potters Bar fire stations. Firefighters, wearing breathing apparatus, evacuated the block and put out the fire.

Radlett sub officer Malcolm Forrest said of John: "He had taken a lot of smoke. He was obviously having difficulty breathing."

He added that John would not have recovered straight away, just by breathing fresh air, because deadly carbon monoxide would have collected in his bloodstream.

Borehamwood Station Commander Danny Rickett said: "Had they not had a smoke alarm they would have certainly died. Without an alarm, in a couple of minutes, they would have been overcome by the fumes. Two lung-fulls of smoke can render someone unconscious."

Heather, a church secretary in Watford, said: "Our advice to people would be to get a smoke alarm. In the past it has been frustrating and we have taken the batteries out after burning toast. But now I would prefer to have burnt toast and a screeching alarm than to be dead."

Following the blaze, the couple had to find a temporary home because the flat was covered in thick soot and their possessions destroyed.

John, Heather and three of their neighbours, including a pregnant woman, were taken by ambulance to hospital in Watford, where John was kept under observation until 2pm that day.

Mr Rickett said although fires were rarely caused by electrical faults in appliances, people should unplug older electrical equipment overnight.

Hertfordshire Fire and Rescue Service has entered into a partnership with Ridgehill Housing Association, in Borehamwood, to get smoke detectors installed in all the association's homes.