We highly recommend you pack a 9" or larger (if you can fit it into your luggage) portable fan.
We read this somewhere while planning for our cruise and knowing we would be going south in a warmer month we did not want to be stuck in a hot room.
Sure enough, our room temperature was not to our liking and switching rooms was not an option. The maintenance team on the ship checked the AC twice and said it was working to full capacity and there was nothing they could do. Housekeeping does not keep fans on board.
In the elevators while moving about ship from floor to floor a lot of people were saying the temperatures in their rooms was not that comfortable..especially if you like it very cool when you are sleeping. And it's even worse when you are sun burned!
We packed a fan and are super glad we did, it's the one thing now we will never travel without!
If you are the type of person who is always cold and wears a sweater in the summer this post probably won't apply to you. But I know there are a lot of people who don't like stuffy rooms and most of all need to feel some air movement/circulation while changing clothes etc...