London: A British internet "prankster" had to be freed by firefighters after cementing his head inside a microwave oven, the media reported.
Fire service officials said it took an hour to free the man after they were called to a house in Wolverhampton city, reports the BBC.
Friends had managed to feed an air tube into the 22-year-old's mouth to help him breathe, the service said.
A senior official said the man "could quite easily have suffocated or have been seriously injured".
"He and a group of friends had mixed seven bags of Polyfilla (cement) which they then poured around his head, which was protected by a plastic bag inside the microwave.
"The oven was being used as a mould and wasn't plugged in. The mixture quickly set hard and, by the time we were called, they'd already been trying to free him for an hour and a half.
"It took us nearly an hour to free him," the official added.