Most American homes are designed and built to impress, not to deal with heat (and sometimes, not to deal with cold, either).

Thermal convection can help, but you would probably have to make some changes in your house. Have intake vents near the floor on the shady side of the house, have cooling shrubbery (preferably kept damp -- use greywater) always shading them. Have high vents near the ceiling on the opposite side of the house.

The more the sun shines, the faster the air in the house/room heats up and rises, escaping out the upper vents, and pulling in more cool air from the lower vents. It stops when the sun goes down.

Many homes in the tropics are built off the ground. If you live in a place that is routinely hot in summer, build a deck off the ground, add an overhanging roof and screening. Or build a treehouse.

The more concrete and asphalt you have around you, the hotter it will be.

Get a copy of Art Ludwig's Create an Oasis with Greywaterfor ideas on how to direct greywater where you need it. The NEW edition contains his branched drains system. Greywater can help cool as well as grow things.

Sue