system
A chat on subreddit /r/pcmasterrace
human
Come to think of it, why don't all Americans measure their PC temps in Fahrenheit when they use it for everything else? 

Probably because Celsius is the default in every monitoring software and it's used in all the reviews, but still.
gpt
Monitoring software, reviews, it's how every techtuber refers to temps, it's how people online and in forums almost always refer to their temps... It's just the default. The standard. The way a metric is supposed to be.