They're pointing out that 50C is not really a liveable temperature so by definition "a room that is typically 51-52ish" can not be celsius, especially not as this is with AC given the context.

That much was clear, but 50C is well beyond where heat strokes start to be a thing, so it sounded weird. Perhaps they're from a place like saudi arabia where there are populated places and it can actually ever get close to 50°C? Hence my remark.