In nightclubs I always film with rain cover. That’s a pain of course but when you undo the cover at the end of the assignment its sticky, smelly and wet so always bring protection when entering the nightclub 🙂
You can use an UV filter or just some screw on protector, but it always makes it a little bit softer, and you’ll have lens reflections with all the disco lights in the camera so it protects your lens but does not make your picture better.