I think the coldest day so far this winter, down to 6f (-14c); and while I’m indoors right now, the wind is blowing so it’ll feel colder still! Brrr …
However, it’s made some very pretty frost patterns on the Kitchen storm door:
Cold and frosty
M&I / GBMINI 
This takes me back to when we lived in the council house. It was long before double glazing or central heating. On winter mornings there would be icy patterns on the inside of the windows, and the curtains often used to freeze to the glass. It didn’t do us any harm! Stay warm.
Keith