Under the Covers

Recently my boys have been doing this completely goofy thing at naptime. I'll go to check them after they have fallen asleep, and they have pulled the covers over their head. Then I pull the blanket off their face, and they're always sweating profusely. How can this be comfortable?!
The other naptime, I had to pull out the camera...
Elijah:

Isaiah:

Maybe I'm the weird one, but I have to be able to breathe when I sleep.