The other day I was at a friend's house, sharing supper with her and her family. She had a large bread tray coming out of the oven, and no place to set the tray because her hot pads were already in use.
I grabbed a couple of hardbacks from the living room coffee table, flipped the books upside-down to protect the front covers, and laid them side-by-side on the dinette.
Bingo! Instant hot pads! (Just be sure the books are of equal thickness.)