A homeless man died in a fire at Helston boating lake after the shed he was sleeping in was set alight by an electric heater, an inquest has heard.

Mark Anthony Trudgeon, 41, known as Mack, died from a combination of smoke inhalation and severe burns after the fire took hold in a former workmen’s hut in Coronation Park on the night of March 22 last year.

Assistant coroner Barrie van den Berg heard a written post-mortem statement from Dr Russell Delaney which said Mr Trudgeon had an elevated level of cyanide in his blood which would have come from a burning plastic boat which was in the shed.

He also had a blood alcohol level of 154 milligrams per 100ml, almost twice the UK drink-driving limit of 80 milligrams, and although he was a heavy drinker who would have been less affected by such a high level, Dr Delaney said it “might have led him to be sleepy, and he may not have woken up and was likely overcome.”

The inquest heard a statement from Terrence Rees, who had been staying in a shed next to the one which burned down, said he had seen Mr Trudgeon drinking heavily in the hours leading up to his death.

He said: “At 4pm I was in the first shelter when Mack turned up, he was drunk.

“He wanted to sit down in the shelter but was so drunk he was falling all over the place. He asked for tobacco, then dropped my pouch all over the floor.”

He said he went to the “shed with the brown door” where Mack slept at around 6pm, and found him curled up in the centre of the floor on a wet sleeping bag he had found in the park.

He said: “I offered him my spare, dry sleeping bag but he didn’t want it. But I threw it over him any way.”Mr Rees said the shed used to be somewhere for council workers to eat their food, and still had a supply of electricity, which he used to charge his mobile phone, although he would only use it in dry weather because he had seen green sparks coming from it when it was wet.

He said: “Mack had the heater on. I knew this because the heat hit me as I walked up to the door.

“I said to him he should turn the heater off, and he said he would later.”

Mr Rees tried to turn the heater off, but he had a bad leg which meant he could not reach the corner where it was plugged in. He returned to his shed, but said he tried to stay awake because he was aware that when one drinker moves to a place it often attracts others.

Waking up later that evening to go to the toilet, Mr Rees smelled smoke, but could not see where it was coming from until he returned to the shed for his glasses.

He said: “I went to the brown shed and smoke was coming out. The metal door was scorching hot, I burnt my hand.”

He managed to get the door three quarters open, but could not get through the gap, and said he wasn’t sure if anybody was in there, and added: “I tried to get inside, but the flames flashed up at me. They were huge, and I crawled back to my shed.”

Finding his mobile phone, he called the emergency services, and used a torch to alert fire fighters to the scene when they arrived.

Group manager Andrew Barrett said Cornwall Fire and Rescue Service received a call at 22.39pm on the evening of March 22, and the first crew to arrive at the boating lake saw Mr Rees’ torch and ran towards it, where they found the shed “well alight.”

He said a fire investigation on March 23 showed “the most likely cause to be an electric heater at the rear of the shed that was on top of other combustible items such as books.”

He said Mr Trudgeon “probably became slightly aware of the fire but only managed to turn around and make it to the left hand corner of the shed, due to the smoke, before being overcome and not being able to get any further.”

Recording a verdict of accidental death, Mr van den Berg said: “Mark Anthony Trudgeon tried to spend the night in a workmen’s hut.

“With the effects of the alcohol he probably slept through what was happening.

“He probably succumbed to [inhaling] the burnt materials as well as the direct heat of the fire.”