what is this chi, mental energy ?

Yes, there was a doctor in China that did the same thing.  People that have experienced great trauma, like being in a war zone tend to pick up telekinetic abilities for a short period of time.  If left untreated it leads to heart and liver disease and stroke.  However with you being able to channel this reaction has possibly redirected the energy.  The leakage however must be allowed to heal.,  So it may not be a safe practice.  Research conducted by the University of California, Berkeley included Thiamine supplements along with Vitamin C, in order to heal the neuroligical process of patients.  You want a physician to work with you on this so that you can closely monitor your vitamin C intake.  You don't want to take too much.

You not comprehend Ki in Japanese or Chi in Chinese. Accupuncture stick needles in Ki points that have flow of vital energy to various body parts. Dim Mak attack these vital points. Scientists never find any evidence Ki really exist. I think this is just your imagination. 

No, that's not what chi is.  You're talking about the new-age "energy ball", not chi.  The new agers are interested in parts of eastern religions, but the energy ball is something they just made up themselves.

Chi comes from Asian religions, and it's generally described as a natural life force.  The closest thing in western mythology would be the Force from Star Wars, only without the ability to levitate stuff or do the mind-trick.  Chi is an energy created by and used by all living things.

I've seen believers use their chi to perform some pretty difficult things, but nothing truly outrageous.  Nobody has ever been able to prove that chi can do anything a trained human body can't do.

You missed out on that one. Gary K told us all about how he did a ten year study on Chi but unfortunately, he forgot??? I personally, have read and seen vids of people lighting a fire with the bare hands and ramming a chopstick through a Formica top table. I don't know about the chopstick but with a little trickery. I can also light paper with my bare hands. It does amaze people and you can carefully examine my hands directly before and after but it is still just a trick of my own making.

You might benefit by reading Autobiography of a Yogi, as the author discusses such siddhis or powers:  https://www.ananda.org/autobiography/#chap26

Also,

The Path of the Higher Self.

Sounds very similar to working with your aura. You can use it receptively or defensively, and can expand or contract it at will, although it takes a few moments.

When I've been with others sensitive to these things it is quite obvious. I also pick up my partners and she on mine, so we don't have to talk to know emotions. Even people who are not used to what it is notice a difference and then usually get a bit afraid because they don't understand what is going on.

When building it out defensively there is a sensation of the body working harder and I do tend to heat up too. Other people feel a push, and often step back at that point.

Try looking into any information on Auras or protection that may give you more insight.

Yeah dude, everyone has warm hands, it's not magical imaginary energy. 

Chi is mythical.  It doesn’t exist in reality.  It has no scientific evidence or plausibility.  You’re  most probably experiencing psychological effects and cognitive biases.