My coworker keeps running the AC because they say it's hot, and it's killing me

The temperature outside is 14°C, but they're still wearing short sleeves and running the AC because they say it's hot...
They've been running the AC since April this spring, and it was cold then, but now it's freezing....
I thought I should just dress warmer, so I even put on a suit jacket, but I'm still so cold that
I eventually turned off one of the three AC units... even doing that makes me feel so self-conscious ㅜ
Other employees are also saying it's cold, but they keep turning the AC on because they say it's still hot.
Since they are my senior, I can't even speak up properly, and it's really tough...