This is why you see a number of hotels linking the A/C (and electricity etc) to keycards. If the keycard isn't in the slot, then the A/C isn't running.
..until someone finds out that whatever plasticky card you got in your purse doubles up as a keycard just fine - something just has to disengage the NC contact...
Edit to add: and also keeps the outlets on (charging your phone, ...) and the lights if you so desire...
Edit to add: and also keeps the outlets on (charging your phone, ...) and the lights if you so desire...