YouTube pranksters build their audience through daring and outrageous videos — but this time they might've gone too far. 

TGFbro, a 22-year-old prankster who has 3 million subscribers on YouTube, mixed seven bags of Polyfilla, and then, with the help of some friends, poured it on a microwave and put his head inside. 

The prankster had a plastic bag around his head with an air tube for breathing. But as he started to struggle to breathe, TGFbro asked his friends to free him.

After some 90 minutes of failed attempts, the group decided to call the fire brigade. 

Emergency services arrived at 1.49pm to the house in Fordhouses, Wolverhampton.

Watch Commander Shaun Dakin, who's in charge of the West Midlands fire service crew, said: “As funny as this sounds, this young man could quite easily have suffocated or have been seriously injured. Taking the microwave apart was tricky, because a lot of it was welded.

“We video-called our technical rescue colleagues for advice and eventually managed to get him unstuck.

“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.

“It took us nearly an hour to free him. 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.”

The prankster posted the video on his YouTube channel and on Twitter, calling it a "near death experience": 

But West Midlands firefighters weren't impressed: