I've taken two naps today, neither of them being in very good locations >_>
First one was on the mini-sofa in this room, I had my head on the arm rest and I woke up with a really sore neck. Not too much later I fell asleep on the mat in the living room (the one i've been complaining about) and woke up with my hip hurting. The sleep was nice, the hip/neck pain not so much.