My girlfriend is using my ~4 year old Macbook Pro, and it's getting warmer and warmer. It's too hot for direct contact with skin. Also, it's starting to drop th

My girlfriend is using my ~4 year old Macbook Pro, and it's getting warmer and warmer. It's too hot for direct contact with skin. Also, it's starting to drop the Wifi at high temps. The battery has been replaced once already. As a result, we're looking at one of those unibody 13" Macbooks, those are reported to be cooler. Temperature is the only reason we're getting rid of this one.