I am not experienced with cats much, but what I think is he's either decided that he's too lonely, notices you're sick but you don't know it, or he is sick.
it is broken
That would be called a "nightgown."
Overheating
You do something that reminds you of him/her. Or maybe they're thinking of you.
If it was grumpy or disturbed, while eating or sleeping.
you don't and it would not be healthy if you did.
Could be a head gasket issue, what color is the smoke? Anyway check that first.
Because many of the creatures they eat are nocturnal. It would be no good hunting for prey during the daytime when they're all sleeping !
Same thing as "let sleeping dogs lie" in the Muggle world. In other words, leave things as they are when disturbing them would start trouble.
Could be water in your gas.
If you have a problem with your sleep you can drink sleeping pills. I would suggest you contact your doctor.
Bad dream? Not enough attention? Scary experiance? Not feeling well?