I personally can't sleep well if its hot. I sleep much better if it's freezing cold, but I'm under my blanket.

I think it might just be that I live in California though. I get sick of the heat. I used to live more east, which was colder and snowed alot. I think it might just be due to taste in a the tempature.

But I think if each individual could find their own personal tempature, then this would be a good technique.