Soooo I’m not sure what an ‘operating theatre’ is (is it a theatre? Is it a hospital? Are we operating?).
Instead of asking what it is here like a helpless dingbat, I looked it up. Sharing for other medically uneducated users. Spoiler alert: It’s just the room in which they operate
“An operating theatre is a special room in a hospital where surgeons carry out medical operations.”