They think it was a combination of musculoskeletal pain and heartburn, both of which he has had before.
None of us slept well, but we're relieved.
I've informed him that he is going to the chiropractor. She (or he) will be able to do something about that musculoskeletal pain.
He's canceling his class today and will be giving his students a take-home final instead of an in-class one.