Five firefighters from the West Midlands Fire Service were needed when an internet "prankster" cemented his head inside a microwave oven.
It took an hour to free the man after West Midlands Fire Service was called to a house in Fordhouses, Wolverhampton. The service said friends of the 22-year-old managed to feed an air tube into his mouth to help him breathe.
"As funny as this sounds, this young man could quite easily have suffocated or have been seriously injured," Watch Commander Shuan Dakin, officer in charge of the crew who responded, said.
"He and a group of friends had mixed seven bags of Polyfilla which they then poured around his head, which was protected by a plastic bag inside the microwave," Dakin said.
"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."
Dakin said that the service's technical rescue crew helped free the man's head from the oven after an hour.
"He was very relieved when we removed a large chunk of the Polyfilla with a screwdriver, allowing him to breathe more easily. But we had to be extremely careful with the screwdriver, working so closely to his head," he added.
"All of the group involved were very apologetic, but this was clearly a call-out which might have prevented us from helping someone else in genuine, accidental need."