So, as the son of a fireman, I have to say this:

If you're going to be playing with fire (as many of us are on the playa) please consider the clothing you're wearing. I saw a young woman in a polyester tutu try to spin fire while drunk last year... it lit on fire twice. Bad stuff. Now, that's an extreme, but here's a few things to consider:

Polyester, as well as most plasticy fabrics such as Vinyl, has a wonderful tendancy to melt to skin when heated. This means if you're wearing vinyl pants or polyblend leggings and your fire poi wrap up on you or you run through a fire, your pants just turned into napalm on your skin and the only way to remove it is surgically, along with the skin it just fused to... and you may not realize the danger until you've already got a patch of that pretty costume you made permanently fused to your side. Please be aware of this if you plan on playing with fire. Also, many of these fabrics release toxic fumes when burned.

Generally speaking, natural fabrics such as wool or cotton burn instead of melting. This is actually a good thing... you can put it out quickly and then remove the item in question. Thicker fabrics such as heavy wool will also block heat for a bit, giving you a moment to do the old stop drop and roll before you're in a serious situation, plus they take longer before they catch. Rayon also does this. As such, these are good fabrics to wear while playing with fire. Leather is good for this purpose too, but remember that fake leather is Vinyl, AKA solid napalm.

Garments with very high surface area, especially poly meshes and fake fur, recieve heat quickly, meaning they burn fast. It's like a thick log vs a bunch of very thin sticks... the sticks catch faster in a fire because more of the material is closer to the heat source. As such, playing with fire while wearing fake fur is a very bad idea, and yes I have seen someone light themselves up quite spectacularly this way.

So yeah, something to think about.