Temperature above 100 F enter dangerous zones just like below 0 enter dangerous zones.

Except that's not true, the deadly zones start earlier than that.

A heat-period is defined as day(s) on which a Level 3 Heat Health Alert is issued and/or day(s) when the mean Central England Temperature is greater than 20°C; between June and August 2022, there were five heat-periods that met this criterion.

https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/deaths/articles/excessmortalityduringheatperiods/englandandwales1juneto31august2022

20C is 68F, 30C is 86F.

While the report does make it clear that these were already vulnerable people who were already expected to die soon - within weeks or maybe months - it was the heatwave that pushed them over the edge.

In the UK, with our brick houses built to absorb and retain heat, and absence of AC, average temps above 20C/68F do kill.

Similarly, it's reported that two thirds of the deaths in the 2021 Texas storm were due to hypothemia, in a state where houses are also built to shed heat. For the majority of the state, as seen in the article below, the temps were negative C but above 0F. I also think it's fair to suggest a good many of these people were likely already vulnerable.

https://www.bbc.co.uk/news/world-us-canada-56095479

I absolutely agree that 0F and below temps are even colder, and even more deadly, but to suggest that is where it starts to be deadly is wrong.

Ultimately how humans experience and deal with tempurature has nothing to do with the scale we use to measure it, but what it is compared to what we are used to and how prepared we are to protect ourself against being "too hot" or "too cold". It's pretty much a perfect example of subjectivity.

If you prefer to use F than C, or K, or any other method, then go for it. But to try and argue that either method is inheriantly better or superior based solely on subjectivity is a fools errand.

Everything in metric is defined around distilled fresh water. The temp scales between 0-100 for solid/ice and gas/stream, and because water is almost incompressible then weight, quantity and volume all interact as well (1kg of water = 1 litre, 1 metre^3 = 1000kg = 1000litres).

Is that easier? I bake a lot, so not having to measure volume for water and instead being able to use weight as a 1:1 conversion sure makes easier when hydrating mixtures - but my oven being at 200C or ~400F makes no practical difference. Again it's just what we're used to.

That said, and I get why they were invented, but using cups, and thus volume, for compressible ingredients like flour honestly makes no sense. But now we're wildly off topic.