news of course is that you have to be cold to achieve this. and who wants to be cold??
for myself i have adopted the habit of sleeping cold. depending on room temperature, i just use the thinnest little cover. i sleep so that when i wake up at night and touch my skin, it is cold. this leads to a much higher calorie burn rate at night. but you will now ask: is it not uncomfortable to sleep in the cold? the answer is surprisingly no. it happened over a couple of years for me, i would just always be hot at night and started to use less and less 