American is best tho. Here's why:
0°C: extremely cold, you're dead
100°C: skin-meltingly hot, you're dead
OR
0°F: pretty cold but you'll be ok
100°F: pretty hot but you'll also be ok
0° C = 32° F
So, cold, but definitely not "extremely cold, you're dead" at least not quickly or more so than 0° F
You might be thinking of 0 K, equal to approximately -450° F. And yeah, undeniably going to kill you. This is the temperature at which it is so cold that there is no movement on a molecular level. It's also only a theoretical temperature, it can't actually get that cold
0°C: extremely cold, you're dead
100°C: skin-meltingly hot, you're dead
OR
0°F: pretty cold but you'll be ok
100°F: pretty hot but you'll also be ok
So, cold, but definitely not "extremely cold, you're dead" at least not quickly or more so than 0° F
You might be thinking of 0 K, equal to approximately -450° F. And yeah, undeniably going to kill you. This is the temperature at which it is so cold that there is no movement on a molecular level. It's also only a theoretical temperature, it can't actually get that cold