I was using a Dremel to make the aluminum shell on a new lightning cable (long, braided) fit through the hole in my iPhone 6S+ case.
The aluminum shell got extremely hot. The cable seems to charge fine (didn't try data transfer), but I'm neurotic enough to worry that maybe the chip is somewhat damaged and something bad could happen in the future...Neurotic, right?
Also, I scraped some of the contacts (it was my first time using the Dremel!), which I'm guessing is no big deal either...?