On: Clothing for Winter Cycling

Why is it that "freezing weather" starts on this chart at -20°C - literally 20 degrees C below freezing?

Think of a fridge or freezer, the walk-in kind. You can work in a fridge without the winter coat. 0 C is not that cold especially if you're doing any kind of moderate physical activity.

https://www.fda.gov/consumers/consumer-updates/are-you-stori...