Top tip, if you're in a hotel room you can often put any card like item (e.g. loyalty card) into the slot and it still works.
This works at a lot of chain hotels. Not every hotel, but a lot of them. In the UK this works in most Premier Inns and Travelodges, doesn't work in Point A hotels from experience.
Alternatively ask for two or more cards at the desk.
If the room is cleaned daily the cleaners have a tendency to remove them though. The chain hotels only tend to clean if you ask though, or on a certain few days after check-in.
Helps if you want to keep the air con on or devices powered up.
