[vhold]

I think of <0F and >100F as being when weather starts becoming lethal if you are poorly prepared.

[lifthrasiir]

People can die from "low" temperature as high as 10 C or 50 F.

[warent]

While we're pointing out extreme outliers out of context to the discussion, water can also remain liquid well below 0c https://en.m.wikipedia.org/wiki/Supercooling

[lifthrasiir]

The lethality greatly depends from place to place and that's hardly "extreme outliers". For example Hong Kong's record low temperature is 0.0 °C [1] and a single digit Celcius is considered "very cold"; people can and do die of hypothermia at that range if they are "poorly prepared".

[1] https://en.wikipedia.org/wiki/Hong_Kong#Climate