Heat? But can't you put it on a tray, or table (that table at the hospital that rolls under the bed), or cushion, or your belly, or...
I really don't understand why laptops and SRS don't go well together.
By the way, unless you're a very limited user of computers who just does browsing, reading, watching and a little bit of interacting, I wouldn't suggest buying a tablet. They're mostly just big smartphones, from what I've seen. Of course, I'd figure they're a bit more comfortable for reading and watching activities, but even then, is it really worth it? Unless you get the best of both worlds with one of the hybrid Windows 8 tablets like the Microsoft Surface that are to come, yeah, but then, I have a feeling you get less battery life/RAM/etc. for the same price than if you bought a laptop...