The Physics of Sheets

This past weekend, I bought a set of flannel sheets, most places having sold out of the newfangled adult-sized fleece ones that are this winter’s fad.
Turns out, flannel does feel “warmer” than percale, evidently due to the fact that there is less heat conductivity: a “bumpy” fabric exposes less of the sheet’s cold surface.
Meanwhile, it looks like we are in for yet more snow showers today. Here’s hoping the superior heat absorbency of dark roads protects us all from black ice and other hazards.