If I've learned anything by being on public Forums is that there are basically two groups of people. One group wants or demand to see the completed picture of a jig-saw puzzle first before willing to start on putting it together; the other, whether due to innocent blind faith or lacking in inborne intelligence or sometimes both, are willing, at the risk of coming up with nothing, to put in the time and effort to put the pieces together to see if any picture emerges.

And spouting knee-jerk "BS" comments (to put it politely) on any and everything which one has no knowledge or experience of or simply because that is the easiest way out and giving it the flimsiest of authority by saying "IMHO" is no way to learn anything or getting anyone to teach you anything.

As for what the monks did to raise their body temperatures, it is actually not something all that fantastic (perhaps it is to non-chi practitioners) It's a matter of degree of control over the speed one can circulate one's chi. As chi is consciously circulated at high speeds, the body temperature rises, much like a metallic wire heating up. My own training can do this, though to reach the level of the monks, I've to put in much more training. When I was a student in London years ago, and coming from a tropical country, I did it to a much smaller degree to keep warm in winter. At my level, it was quite mentally exhausting to keep circulating the chi at high speeds while listening to boring lectures.

As I've said a long time ago on another thread, Chi is a basic ingredient like flour, which can be turned into bread, noodles or cakes, depending on who is using it and for what purpose.

The question is HOW do you start to acquire contact with and manipulative control over the chi. I've already given the answer elswhere.
I'll rather be happy than right, anytime.