I wonder if there are any photos from bikram yoga. I just heard about it, where they do (or try to do) 26 different postures in sweltering heat (105F!!!) for about 90 minutes (yikes!). A simple youtube search yields some interesting clips, including how the originator himself is/was in the hot seat for sometime.
Here's what wikipedia has to say:
http://en.wikipedia.org/wiki/Bikram_yoga