I used to be an Engineer in the Merchant Navy and visited lots of exotic (and very hot) places. Sometimes the Air Conditioning worked -and sometimes it didn't. I learned a good trick to keep cool at night which is to lay covered with a damp towel across you. I won't bore you with the technicalities of how it keeps you cool (mainly because I can't remember !) but it's something to do with latent heat of evaporation.

CK