Hey guys, I've been vaping my aspire sub ohm batt with the troll rda by watofo. Some guy at the vape shop built a dual coil in it. I honestly don't know the ohms of the coils but my question is: the top part of the battery get quite hot while vaping, mostly the metal area around the button. And of course the rda gets hot. Is it safe to vape on, and is the heat something to worry about?