I think that's probably evaporating sweat or water from the towel that was around his neck. His skin temp is probably super-hot and it looks like everyone else is wearing coats, so I'm guessing it's like when you have a hot tub running in the winter? Anyway, check out how the deflate/extinguish crew is also wearing fire-resistant balaclavas. I wonder what the odds were of that whole mat catching on fire.

My guess would be that they replaced the real glass with 'stunt glass', which is made of sugar, and harmless.

I didn't know this stuff existed before and now I have found a recipe.

Yeah, seconding sugar glass. I imagine that if they didn't replace the tempered glass originally there, he would have given himself two broken wrists and a concussion.

Sugar glass is awesome. I remember that old Jackie Chan film (Rumble in the Bronx I think) where a bunch of gang members threw bottles at his face that shattered beautifully.

Mirrored sugar glass? That's pretty cool.

You are correct.

This personifies a lifetime of dedication and aspiration.

And liability waivers.