Given the kind of protective gear you need to take into such an environment I'd suggest it might be cheaper and a lot less hazardous to buy a couple consumer point and shoot cameras and accept that the only thing you may walk away from the shoot with is the memory cards (assuming you can get them out of the camera). At the very minimum you will harden the rubber on the outside of the D2X and melt all the glue.
A waterproof housing will save the camera from smoke, dust and water but the heat will likely melt all the seals and plastic turning the housing into a melted tomb for your camera. Wet, white cloths slapped over the housing will help to an extent but the only for a short duration.
If you are going inside the building you will likely need to wear a BA set. That will make composing the shot through an optical viewfinder very difficult. Point and shoot cameras have live preview off the rear LCD.
My advise? Buy a some cheapo second-hand point and shoot cameras (from another manufacturer) and enjoy yourself trashing them.
I thought about the Point and Shoot but the quality is just not the same as my D2x The melting point of the water proof housing is just about 400 degrees and I should be outside of the environment before it gets that hot So I think I might go that way Thanks for the pointers I will keep you posted when we do the live burns
Focus on what's right in your world instead of what's wrong
The housing may not melt until 400 degrees, but it isn't a very good thermal barrier. If the outside of the housing is 320 degrees, the inside probably isn't far behind. That will be the danger to your D2X.
It sounds to me like you're a firefighter. I am as well, and I have given some considerable time to thinking about how I could take my D2X into a training burn. I have come to the conclusion that the only way to safely (for my gear) photograph a training burn, or any other burn for that matter, is from outside the structure. If you are going to put the camera in an underwater housing, crawl in the door and be there for less than 15 seconds, then great, I don't think you'll have any problems. But when you figure that the average training burn gets to 350 degrees or so at floor level within a few minutes of starting, that just doesn't seem like the environment I am willing to take my D2 into. I thought about wrapping the camera in nomex hoods, turnout liners, glove material, etc. but just couldn't come up with anything I felt comfortable with. The biggest problem I see is that one way or another you have to expose the camera body to the heat unless you create some kind of a closed bag that your hand is inserted into, and you will expose the front element of your lens to high heat no matter what. If you come up with a workable solution please share it as well as the images with us, as I know they will be great. Best of luck.
Robert Olmstead Healer of Men Elf Friend Level 5 Geek
I would get a used Ikelite underwater housing for the D100 and a used D100 as both should be pretty cheap at this point in time. The Ikelite housing is a polycarbonate plastic that should not melt from the heat. There would be enough extra space in the housing to put in some gel packs like the Ace reusable cold compresses.
You can get borrow a similar housing from a diver/UW photographer and put a thermometer inside and do a test run without a camera inside. This is actually a good idea the first time a housing is going underwater as well.