Put a powerful processor ( Atlhon 64 bit) in a small case (laptop), the result is predictable.
There was a court case bought by a Swedish man (whoelse?) agaist a laptop maker. He put the laptop on his lap for long time, the certain part of his body (you know where) got burnt. His argument was that the laptop should be safe on lap. He lost his case, but it was a great laugh. This is a really case.
So, do not put laptop on your lap for long time especially Powerful ones.