100°C is an acceptable sauna temperature. You won’t last much longer naked in 0°C!
Edit: To make my point more clear, I know some crazy people who go directly from a close to 100 degree sauna to a close to 0 degree ice bath. I think that could be described quite well as going from 100 to 0 % within the human temperature tolerance.
Also, that’s not my initial point. My initial point was that “percent hot outside” means nothing in Fahrenheit or Celsius.