Ask HN: Does anyone know anything about tummo meditation? (raising body temp.)

I'm very curious to learn about tummo meditation. I searched extensively for it a few years ago. I learned about vase breathing being the first step.

I've trained the Wim Hof Method (WHM) with Wim for 4 days in Poland in 2014 and have used it on and off in my life - mostly at festivals to enjoy the music more. He explicitly told me that what he teaches is not tummo meditation. Nowadays he also tells it on the web [3].

The issue is, I can search more on the web but what I find hard is to assess whether the knowledge is reliable. This topic has never been discussed on HN and I think it really should since tummo meditation has very interesting side effects [1, 2]. For example, monks practicing tummo meditation can raise their body temperature at will.

I wonder: is anyone on here knowledgeable about practicing tummo meditation?

Has anyone studied the science of it?

Edit: I see that it is discussed here [4].

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3612090/

[2] https://www.youtube.com/watch?v=oCXr7rxTLBE&ab_channel=MrVikas07 - 3 min. video of Dr. Herbert Benson explaining it.

[3] https://www.youtube.com/watch?v=Yo2yy6EbOJ0&ab_channel=WimHof - warning he screams somewhere at the beginning of the video. Another warning: Wim makes many claims that have no scientific backing. Yes, scientists have studied him but he goes far beyond the studied claims. I use the studied claims to increase adrenaline levels in my body at will, so there is a practical use to his method (other than being more comfortable in extreme cold evnironments). For example, self-imposed adrenaline is a good painkiller when you don't happen to have one on hand. To get a glimpse of what adrenaline levels WHM practitioners can reach read: https://www.pnas.org/doi/10.1073/pnas.1322174111

[4] https://news.ycombinator.com/item?id=21638225