London - A UK man who fell from a hotel balcony and froze to death overnight had been sleepwalking, his family believe.

Rob Williams, 27, who had been a sleepwalker since he was young, had gone to the hotel with colleagues following a work party when he fell nearly 4 metres.

The building surveyor was found suffering from severe hypothermia on a roof outside an unoccupied first floor room the following afternoon when he failed to show up for work. He spent five days in intensive care but died on Christmas Day without regaining consciousness.

On Thursday his girlfriend of four years, Carla Hilton, wrote on Facebook: “I am completely lost without you. When my phone beeps, I hope with all that I have that it is you. When a door opens, my heart races to see if it is you. With every minute that goes by, I think of you, talk about you, cry because I need you.”

Williams’s sister Kirsty Ashby, 30, revealed that her brother had climbed out of a window on to a balcony at the De Vere Theobalds Park hotel in Waltham Cross, Hertfordshire, before falling.

He was taken to the Princess Alexandra Hospital in Harlow, Essex, then transferred to Basildon Hospital. Doctors warned his family that he was unlikely to live but, incredibly, he started to show signs of progress. But brain tests showed that he was not going to recover and on Christmas Day his family decided to turn off his life-support machine.

A post mortem examination revealed Williams, from Chelmsford, Essex, died from brain injuries caused as a complication of suffering from severe hypothermia.

It is not known whether after the fall he was knocked out or simply stayed asleep.

His sister, of High Wycombe, Buckinghamshire, confirmed that Williams had been a sleepwalker since he was young and his family believe he had been sleepwalking when he fell. She said: “We knew Rob sleepwalked but I don’t think any of us knew how bad it was – it’s only been from talking to his friends that we realised the extent of it.

“But it had never caused him any problems before.”

She added: “My parents are just struggling to take it all in at the moment. It has been an awful time for us all.”

Of her brother, she said: “He was a really fun guy, someone you would always look forward to seeing. He was very funny – a pleasure to be around.”

Williams was not a guest at the luxury Georgian mansion but had gone back there with colleagues who were staying at the hotel following their Christmas party.

He and two colleagues stayed in a room and, the following morning, they initially thought he had gone to work. Concerns were raised when he didn’t show up.

Hertfordshire Police are treating the death as non-suspicious. A file has been passed to the coroner.

Up to 15 per cent of the population sleepwalks

Sigmund Freud thought it expressed a desire to return to one’s childhood sleeping place

It can be passed on in families and is most common in children aged three to seven

Most episodes last ten minutes and, contrary to popular belief, it is safe to wake a sleepwalker

No specific treatment exists, but hypnotherapy can help. - Daily Mail