Then you haven’t spent time in China and realise they use their hospital system very differently. Often people will go to hospitals for minor fevers.

Yep, can confirm this took me by surprise when working with chinese colleagues in our company. Eg. I would read someone's out-of-message saying "OoO, going to hospital today" and be freaking out. But then they would be just out for couple days sick leave for fever or something. Only after like 3rd time that happening it clicked to me that 'hospital' for them means something completely different than I would have thought.

Whether that is just a misunderstanding of language or actual difference in healthcare system I never thought about.

"Hospitalized" normally refers to staying at the hospital, not just visiting the ER, though it is a bit ambiguous.

So typically they have a "fever ward" and you will go there and receive an IV of Tylenol or something similar. I would be surprised if they didn't call that "hospitalisation". You are admitted, given a bed, a chart... not sure what else you'd call it.