Originally Posted by LeighHop
I found some info that says your body does actually work harder when you work out in the heat because it has to struggle to control its internal temp.
That makes some sense, but I shouldn't think it enough to really make a major difference in terms of calories-burned. You definitely should drink extra water after you've finished if you're sweating/glowing extra though, to replenish all those lost fluids.
Just do what you do and work as hard as you can. You'll get your results, with or without a super-hot room!
(Incidentally, my favorite treadmill at the gym is the one directly under the air-conditioning unit. I still sweat while I run, and my hair gets wet, but my clothes don't get quite as soaked through as when I run on one of the other treadmills. Whatever the difficulties for my body in regulating its temp without the air-conditioner, I still find that it takes 32 mins of running to burn 300 calories.)