I was going to suggest CO2 might be an issue in a room. CO2 in the bloodstream upto 30% saturation has a stimulating effect which make no ventiliation in bedroo

I was going to suggest CO2 might be an issue in a room. CO2 in the bloodstream upto 30% saturation has a stimulating effect which make no ventiliation in bedrooms a common reason sleep is not restful, over 30% saturation level it has the opposite effect and can then be viewed like a noble gas and the effect noble gases can have on the body, namely it can kill and the body doesnt react.