Negative mass & wet bed sheets

This morning I was reading once more in one of my books about how the expansion of the universe first was found to be accelerating,in the late 90's, which led to the revival of Einstein's cosmological constant, and how unsettling and unbelievable the finding of the acceleration was to scientists around the world. It gave the appearance that the universe contained a negative amount of mass.

To me, these findings appear far less puzzling though. They're still interesting and fascinating, but after all, the physical universe is only a secondary phenomenon. It could turn out to be anything therefore - because in the end, matter will turn out to be just an illusion. An extremely persistent illusion for sure - especially at times when you're cold, or in some other ways miserable or in pain, as I was on this bitterly cold morning,struggling to get myself ready to leave for the gym.

I remembered how I once heard about an absolutely stupendous exercise performed by some Buddhist monks: They would go out to a lake side on a winter evening, and wearing only their underwear they would each drench a bed sheet in the water and wrap the wet sheet around their shoulders, and then in the freezing cold night they would just sit there by the lake side and dry the sheets with the heat of their bodies.
I have only heard about this story, I don't remember where, but I believe they can do this.I even have a pretty good idea as to how they might do it. I think they may be "visualizing" (it involves more than vision, of course) to be sitting under the glaring heat of a radiant desert sun instead, or something similar, and they have the mental power to have this visualized reality supersede the one outside.

Unfortunately, knowing how something may be done doesn't mean you can do it, and so I was still freezing miserably in my room. Only later after starting my workout I felt better as I was finally warming up a bit. I'm hoping to finally get a grip on these things soon, I think it would among other things also help me to deal with my physical problems, such as my intolerance to the brutally cold German climate.
No experiments with wet bed sheets anytime soon though!