It shouldn't be a face matter, rather a hygience if the dust gathered on the pajama and bring them on the bed.
On the other hand, wearing necktie and suit is not so civilized in hot and humid weather. Don't follow the necktie cult. Wasting electricity if air-con needed.
By the way, if Shangaiese girls/women keep their hair long, would it be wasting water to wash? Not green enough. I guess it'd be time for the water saving campaign by the celebrities to cut their long hair.