I have a few tricks for AC-less living. A whole house fan is a great idea, but when the really hot days come in, the cooler nights simply become more humid. Makes it hard to sleep, even with a constant breeze due to a whole house exhaust fan pulling night air through your window. There is a low tech solution to this though. Since your in one place for 7 to 8 hours while sleeping, a very local solution is best. This one is the flip side to an electric mattress pad for winter...
Take a quiet aquarium air pump, some tubing, an air stone, a cheap styrofoam cooler you are willing to cut up, and old sock, and an empty gallon jug.
Fill the gallon jug with water, put it into the freezer.
Place the frozen jug & air pump into the cooler, run the power cord and tubing out the top through a loosely cut hole. Run the air stone(s) to near where your feet would be inside your bed, but under a thin summer topsheet. Wrap your airstone in a sock. Tuck your topsheet in well along the foot and sides of your bed, so that air must flow up towards your head. As the air pump runs, it will slowly pull room air into the cooler, which is cooled by the gallon jug of ice, and push it into the air 'envelope' you created with your topsheet. By the time the air is in the bed, it won't be uncomfortably cool anymore, but it will be dry because the humidity will condense inside the cooler before the air pump pushes it up your body. A quiet pump is important for obvious reasons. The old sock is also important for two reasons, an air stone does not feel good on your bare foot if you kick it in the night, and any air that infiltrates through the topsheet will condense a bit more humidity onto the sock, so the sock also acts as a towel to keep your bed from getting wet if it is an particularly humid night or if your topsheet isn't particularly good and segregating the air spaces.