Newer, faster and more powerful laptops tend to run hotter than older ones, as we all know; with it sometimes becoming quite uncomfortably hot to have our laptop directly sitting on our legs. There's apparently a special name for this – 'Toasted Skin Syndrome' – something that can at best cause some unsightly mottling of the skin, and in successively worse and worse outcomes, may cause permanent discoloration and possibly an aggressive type of skin cancer too.
More details about Toasted Skin Syndrome here.
Interesting, this is as bad for the laptop as it is for you. Heat build up stresses any type of electronic device, and accelerates the aging process of the componentry, leading to shorter lives and earlier failures.
Maybe devices such as this lovely featherweight AViiQ portable laptop stand are a good idea after all, notwithstanding its awful name and $80 price tag. Or, if you prefer, Amazon