I have been doing Power Yoga since 2001 and it helped me A LOT..
the room is heated, we sweat a lot, but I am not sure if it is 100F...I have no complaints at all against it. I got pregnant twice doing Yoga, and it helps me to get more relaxed.
My Yoga instructor know about my infertility problems, and she always tells me which asanas are good for my condition.
Also, Yoga was the only thing that made me lose weight (I lost 10 pounds before taking glucophage xr and 15 more pounds after starting gluco)..
PCOSer - diagnosed in Sep. 2001
TTC - 4 years
DH - internet miracle