Brilliant idea until you dream you're being chased by a bear, and you wake up out of the terror to see that you're lying inside a bear. Then you try to claw your way out of it and in the process wake up your tent-mates. Delirious with sleep, they see a large bear-like thing flailing about in their tent. BEST CAMPING TRIP EVER.
Also on these boards
Sleeping Bag ( I want this)