Oh then we both have terrible news today....

One of my pet peeves is people thinking units of the past or people in the past were stupid, as opposed to just prioritizing different things.

The low end was based on the stabilizing temperature of a solution of water, ice and salt in a proportion lost to time. The benefit was that a water/ice/salt solution will stabilize it's temperature naturally until the ice melts, making it useful for calibrating something like a thermometer: "ice" can be below the freezing point, but you can use the solution to set a steady baseline: the liquid will be 0°F.
The next steady baseline was body temperature, available to anyone measuring.
The scale was then set so that the freezing and boiling points of water were 180° apart. This was useful because it put them on opposite sides of a dial.
It was before we decided that ten was the ultimate number that couldn't be beat, so people still played with circular symmetry, thirds and so one.

This meant you could calibrate your thermometer by setting 0 to bring, 100 to your body, and then pushing steam through it and adjusting the offset so that the intervals were right and you correct body temperature variance. Some specific numbers have changed over the years as we adjust the scale to be based on metric.

Not stupid or arbitrary, just prioritizing things we don't care about so much any more.

Celsius and the other are both based on absolute zero and a very specific change in energy levels in the medium, so it's ultimately moot. Neither is technically based on what they originally were.
https://en.wikipedia.org/wiki/2019_revision_of_the_SI

... Please stop. Its not only not true it is also very silly. No its not good for weather, 78 is not a temp for a room.

Why are you all like this?

For Celsius

0º - water becomes solid - it's cold

25º - water is refreshing - ideal temperature

50º - water is scalding - dangerous

100º - water is boiling - guaranteed serious injure territory from this point forward

And, since nobody seems to reach an agreement...

For Kelvin

0º - matter has ceased to move; collapse of matter and reality as we understand it - it's cold

273.15º - water is remains solid - still cold

298.15º - water is a fluid, drinkable, safe to enter - ideal temperature

323.15º - water is capable of delivering serious injuries upon contact - dangerous

373.15º - water is passing into vapour form at high rythm - avoid proximity and all contact from this point forward

This is not the explanation you think it is, over there.

So I take it 50°F is the ideal temperature for humans, since it's halfway between cold and hot?