Why Do Wires Usually Warm Up When An Electric Current Is In Them A Pimple Under My Right Breast?

A pimple under my right breast? - why do wires usually warm up when an electric current is in them

It hurts. I have a 38C chest is warm in general, where I live, 18 degrees Celsius, 36 degrees Celsius. Sometimes I have tunnel, but when I'm at home, do not wear bras. I have not noticed. I wonder why I have a button there. I do not know whether it is a grain, but it looks like.