Have had my rMPB for 3 weeks now and am loving it, however recently I have noticed that the area where the battery is (between the screen and keyboard) is getting extremely hot when I touch it, practically burning, when I plug it in to charge and use it at the same time. Note it isn't heavy use, just watching YouTube and having several tabs open on Safari. This is my first MPB so I do not know if this is normal. iStatPro said the GPU Diode was around 70C. Could anyone confirm if this is normal?