Admittedly, Papyrus tends to wear dark tights under his battle body; the better to match his walk sprite's portrayal. But those are just thin leggings. They provide minimal warmth, given how little he wears on top of it. His clothing choices are entirely for fashion and morale. There's nothing for getting into the mindset of exercise like a Jog Boy tanktop.

"A dresser...? Like Sans has?" He considers the possibilities, hauling the big snowball on top of the future-car mound. "Oho! I could keep season-relevant clothing in the dresser, and everything else stored in the closet! That would be incredibly functional. And so easy to remember!"