“Memory foam” pillow causes sleep apnea?

On Saturday I took a nap. It didn’t feel restful, and I remember at least once gasping for air. For at least an hour afterward, I felt the need to take deep breaths. On Sunday I had the same experience, only I was alert enough at the end to notice that my chin was resting on my neck. (I don’t have a double-chin.) When I nap, I’ve been using Jordan’s new “memory foam” pillow. It is convex in the middle, so it mainly supports the neck, with only a little padding for the head. The “memory” part is that it shrinks with heat, leaving an impression wherever you touch it.

The problem is that after sleeping for a while, the “memory” means that the neck no longer has any support. The pillow seems to work fine for Jordan, but I’m not going to be borrowing it any more.