My son would love a bunk bed but the room is fairly small and we have ceiling fans so he could hurt himself with the fan it we had bunks.
We have a ceiling fans in bedrooms too (we bought the bunks in our last rental which had no fans). It has just got far too hot here at night, so we've pulled the bunks apart so the kids can have the fan on. Once it cools down again I'll put the bunks back together and tape up the fan switch, so they can't turn it on. It seemed to do the trick for us. Might be an option for you?