With or without wind chill?
With wind chill, fifteen below in Germany, wearing a thin cotton hat that did not cover my ears. Later that week it got to almost twenty above and we took off our BDU tops and got to work replacing truck batteries. Being able to touch bare metal . . .
Without wind chill is was thirty six below in Bloomington, Indiana. No wind at all. Riding a bicycle was safe. The crossover point on the Celsious/Fahrenheit scale is forty below. Mercury freezes there. . .
The Fahrenheit scale defines zero as the coldest condition NaCl can be pounded into ice without the slightest hint of liquid.
Tell your tale.