Internal temperature is measured inside the body (i.e.; mouth, anus), while external temperature is measured outside of the body (i.e.; armpit).
Fever is an abnormally high body temperature - which will often result into the external temperature being elevated as well (warm forehead when sick?).
However, the outside of your body typically rests at a lower temperature than the inside of your body.
All fevers are internal. Fevers occur when white blood cells are fighting off an infection. It raises your temperature to help them better fight of whatever is making you sick. This increased temperature is a fever and it affects the entire body. Since this is all happening in your blood stream, it's all internal.
I really don't know what you're talking about.