We watched an artist set fire to themselves on stage

Have you ever seen a person set on fire? Of course you have -- you've seen it in the movies. Denethor in Lord of the Rings; Anakin in Revenge of the Sith; vampires in everything from Blade to Buffy. It's a classic of the stunt genre. In the business, it's known as a full body burn.

Last week at the National Theatre in London the US-Canadian performance artist Cassils did a full body burn from start to finish, all the way from the set-up until the last spark had been extinguished.

It seems obvious to say that seeing someone set on fire in front of you is very different from watching it on a screen. In a film, there's that single gaudy flash, the retina-staining conflagration that's the stunt version of a full chorus line: an old-timey piece of showmanship and skill, as well as a bit of an eff-you to CGI. In person, the process is far knottier. Cassils' live performance laid the stunt technology bare: it showed the intricate work, tension and moments of sheer pain that go into making that familiar spectacle.

Cassils' performance work is all about the body, often in a way that borrows from sport. In a piece from 2011, Cuts: A Traditional Sculpture, Cassils worked out how to achieve a masculine ideal of perfection, force-feeding protein and even steroids, gaining 23 pounds of muscle in 23 weeks. In another piece, 2013's Becoming an Image, Cassils attacked a 2,000-pound clay sculpture, kicking, beating and punching it for 20 exhausting minutes.

Given Cassils' sport/art crossover, a minute-by-minute report seems the best way to describe what happened in Inextinguishable Fire.

1 min: As we come in, Cassils stands alone at the front of the stage, naked aside from a pair of black pants. Cassils, who is transgender, has a body that defies easy categorisation. At first glance, they are an extremely fit man with surprisingly pronounced pecs -- that is, until you realise the pecs are breasts.

Cassils gazes expressionlessly over the audience. During the entire process, in fact, Cassils will say nothing. There is no explanation, no reassurance. We are left to guess what is happening -- and, after it is over, to guess whether Cassils is unharmed. "Something I'm very interested in is implicating the viewer in the act of watching," they said after the performance. "They're not just passive people that walk up -- they're part of the piece."

Note 1: On pronouns. Cassils prefers to be referred to as "they" rather than "he" or "she". This can create grammatical complexities, because we need a better word for "neither he nor she and in fact rejecting this unnecessary opposition." In the meantime, "they" will do fine.

Min 5: The three stunt coordinators, who until this point have been milling around at the back of the stage, pull on the hoods of their fireproof suits and begin to dress Cassils in the clothing needed for a full-body burn. The audience stills. The sounds on the stage are suddenly very clear.

Min 6: Two members of the stunt team draw on what look like a set of flesh-coloured tights. Dressing and being dressed by other people is always awkward. Cassils has to lift each leg in turn, holding onto the stunt coordinators to keep balance.

Once you're lit trapped air can burn. The tights are on and the stunt coordinator rolls his hands quickly down Cassils' legs to make sure there are no air bubbles under the material.

A second pair of tights go on. The same brisk rolling.

Cassils shivers. In order to prevent the sweat from boiling on the skin, the person performing the full body burn has to be induced into a state of temporary hypothermia, which is done by soaking the tights in a freezing fire resistant gel. At the exact moment Cassils was preparing to be set on fire, the main physical sensation they were aware of was how incredibly cold they were. After the burn was finished, they took a hot shower to warm up.

Min 7: Another pair of tights, this time made of a shiny black material. This is CarbonX, a flame resistant fabric made of oxidized polyacrylonitrile fiber. The stunt team pull three CarbonX tops over Cassils's head, before tucking them into the CarbonX tights.

Finally, the stunt team pulls on thin socks, followed by CarbonX socks, then thin gloves, followed by CarbonX gloves. The last items in this stage of preparation.

_Note 2:__This particular stunt team is led by Marc Cass, a veteran British stunt coordinator who has worked on_GoldenEye,Saving Private Ryan,Titanic_and_Terminator 3--where, incidentally, the female Terminator is burned to a crisp, only to reemerge as an angry killer robot. "The thing about fire jobs," Cass tells WIRED, "especially full body burns, is that when they go wrong, they go very wrong."

Min 10: Cass and his stunt team begin to dress Cassils in a padded Nomex suit, like one you might see a fireman or a racing driver wearing. This is followed by a padded white suit, made of cotton, a non-synthetic material, which won't release harmful black smoke when it burns. ("So it won't poison them and collapse their lung," says Cass.) Wrapped up in this way, Cassils begins to look very small, and strangely more vulnerable than when they were naked. The tension in the room is now very evident.

Finally, Cass and co fit and lace a pair of Timberlands onto Cassils' feet, a weirdly pedestrian note amidst all this high-tech suiting.

Min 12: While Cass finishes tying Cassils' boots, a second stunt coordinator begins to coat Cassils' face and hair with a thick translucent gel. This is another fireproofing substance, the exact recipe for which is a trade secret. Cass says the main ingredient is tea tree oil, mixed with various gel emulsifiers: "It keeps the skin very cool."

Min 14: Cassils is hooded with balaclavas made of CarbonX and Nomex. All we can see now is the area around their eyes, which is then coated in gel by the second coordinator.

This coordinator seems to be going a bit over the top. He fills in Cassils' eyes, slapping the gel on thickly with his fingers. He even fills in their nose, to the point where Cassils has to start blowing to try and clear it. Cass asks if they are okay and Cassils responds by waving a gloved hand in the direction of their face. "The stunt coordinators were very professional, and had done this many times for film and television, but they've never been on stage," says Cassils. "All of a sudden these people that are usually behind the scenes, become performers. And I think -- I know for a fact -- they got stage fright. All of a sudden I see his hand shaking. He's covering so much goop on my face, ramming it up my nostrils, so I couldn't breathe. It was a little unnerving to have in someone who was supposed to be calming me down."

When I ask Cass about this, he says: "There is a little bit of apprehension there. It was exciting, it really was. And to be responsible for that, and to make sure [they're] safe -- it was a bit of an undertaking. I felt for Cassils. It was almost as if I was doing it myself."

Note 3: On insurance. Cassils performed this particular full body burn without personal healthcare insurance. Stunt artists on a film are covered as part of the film as whole, but no-one would insure Cassils for a one-off performance. That is why, Cassils explains over email, this stunt will never be performed again.

"I will not do this piece due to the risk. It is impossible for me to secure workers compensation insurance so if I were to be injured I'd be out of a job. Likewise the medical bills would bankrupt me. My wife and I had an agreement to get a divorce to protect our assets should I have been injured and incurred inevitable mass medical bills."

Min 16: Cass pulls the hood of the suit over Cassils' head and fastens the front, leaving Cassils shrouded in white. Using paintbrushes, the other two stunt coordinators paint Cassils' front and back with a clean-burning fire accelerant, going up to the waist. The moment is getting very close. Cass adds one last coat of the gel around Cassils' eyes. "One minute," he says to his team.

Min 19: Cassils asks Cass to clear their nose for the second time. While he does, the other members of the stunt team paint accelerant on the arms of Cassils' suit.

Min 20: This time, the nose-clearing seems to work. Finished, the stunt team step away and out of the spotlight. Once more, Cassils appears to be alone on the stage. "Absolute silence please," says Cass. Then he lights a piece of wood.

Min 21: With the burning stick in his hand, Cass makes one final adjustment to Cassils' hood. "Deep breath," he says. Cassils has to hold their breath throughout the duration of the full body burn -- if they breathe in, the fire will scorch their oesophagus.

Cass steps back, and the two share a look. Then, with practiced swiftness, Cass steps forward and hits Cassils on both legs, saying as he does so: "You're on fire." "You sometimes can't tell you're on fire and you don't want to look down to see you're on fire," explains Cass. "You don't want to put your face in the fire. It's very important you keep your head up."

The flame catches instantly, shooting up the body, and as it does, the lights go out. Standing still in the middle of the stage, Cassils burns. Some people are covering their eyes with their hands. The rest of us watch, compelled. It's scary, but mesmeric.

The whole burn lasts for 13 seconds -- but in this context time is almost meaningless. Seeing a full body burn in person is like seeing a fight on the street, when before you've only seen them in movies. It's nastier and quicker, but at the same time it takes longer. There's no plot to explain it. It makes no sense: it is stark, impenetrable, violent.

Note 4: On violence. In Cassils' work, violence is the word that crops up again and again. Violence against trans people, violence against people of colour, violence against the self. The title of Inextinguishable Fire is borrowed from Harun Farocki's 1969 film protesting napalm production during the US war on Vietnam.

Farocki said in the first minutes of the film: "When we show you pictures of napalm victims, you'll shut your eyes. You'll close your eyes to the pictures. Then you'll close them to the memory. And then you'll close your eyes to the facts."

Cassils knows they are not truly being burned, in the same way that napalm victims were burned; all the same, they say: "By exhibiting violence I am drawing attention to it." The images of violence we see contain no violence, leading to the assumption that they are created painlessly. Cassils' art fills in the blank.

Min 22: "Down!" calls Cass, and Cassils falls to the ground, crushing the fire beneath them, as the stunt team rush in with fire extinguishers. Cassils disappears in a cloud of white dust. The fire is out -- but is Cassils safe? Nobody seems to move. And, then, Cassils appears, rising out of the mist, breathing in a single gasp of air.

Then, immediately, before we're reassured about their wellbeing, Cassils and the whole team are gone, leaving all of us to clap at the empty stage. "Leaving people to wonder what happened -- there's something really powerful in that," says Cassils. "And if you're wondering that about this simulation, what does this mean about people who are really burning, and what does it mean about distance?"

Min 30: We leave the auditorium slowly, as if we have seen something that troubles us. Outside the theatre, we are ushered out onto the South Bank and asked to stand by the side the Royal Festival Hall. Cassils has projected a video of a previous full body burn right across the side of the building. Unlike the sparse performance we have just seen, however, this burn is filmed in a highly stylised way: it unfolds in extreme slow motion, then reverses back to where it started.

As the video plays, people start checking their phones. They begin to talk. They take pictures of the film and share it on Instagram. The film is sucking the life from the live performance. It's the same act, but on a screen, even this gigantic one, it is completely different. Of course it is -- but having seen what we've just seen, we know that better than ever. "I was interested in juxtaposing the live performance with the mediated image to see how your response as a viewer was changed," says Cassils. "[To make] one that would tighten your gut and would make you feel sick, and one you could pass by."

Two seemingly incompatible elements placed side by side. For Cassils, this is not just art, but the work of life.

This article was originally published by WIRED UK