Cold Books

I went to the library this morning and brought a few books home for the kids. After lunch Lily went through the bag examining the books. She picked up a "Princess Penelope" book at started to flip through it. The plastic jacket was beginning to come off so she took it all the way off and here's our conversation:

Lily: Mommy, what's this (holding up the book jacket)
Me: That protects the book, it's called a book jacket
Lily: Mommy, is the book cold?