Must be a tolerance thing. I’m in the southern part of Texas where most nights I’m too warm, not cold. I never realized so many people burrowed too!
The three females love to burrow. The male can’t stand it. Pixel will head down around my feet. Havoc will stretch along my belly, and Brindle will curl up under my chin.
They don’t pick on the wife until I get up to head off to school.
That would make sense, if it’s been established that CO2 will actually build up under an ordinary blanket. Does anyone have a cite for that?
No cites, sorry.
Just theory pending testing and the scientific method. 
I felt my blood CO2 levels rise just reading that …
:eek: < ---- gasping for breath
I do this, but only when I have a cold or sore throat, and for exactly this reason. Generally, I have sore throats mostly in winter, when the air is dry dry dry, and I imagine that keeping my nose under the covers irritates my throat less because the air is more humid.
Doesn’t stop me from hating it, though - I’d much rather leave my nose out of the covers. Which is why I only sleep with a covered nose when I’m sick.
My mother always used to tell not to sleep with a sheet/blanket over my head because I might suffocate in my sleep, but I’ve been doing it for 25+ years now and it has yet to prove fatal.