Many historic homes in Des Moines were constructed before air conditioning was invented. Prior to the age of freon, people used various "passive" methods for cooling themselves during the hot months of the year.

The "Natural Living Des Moines" blog has a great post on some easy ways to stretch your cooling dollar. Here are their ideas (with some commentary by me):

• Open the Windows - In addition to what they say, if your windows are the double hung type (both the top and the bottom sashes are operable) open the bottom one halfway and pull the top sash down halfway. This will allow hotter air to escape out the top and cooler aire to enter through the bottom openings.

• Keep the Air Moving - Ceiling fans are a great low impact alternative to lower the air temperature at your skin. Air moving over your body facilitates the cooling effects of evaporation.
• Don't Make the House Warmer - Avoid running appliances that create heat like ovens, light bulbs, computers, stoves, and dryers (your refrigerator actually creates heat in the kitchen, but don't unplug that one). Try grilling your dinner outside and hanging your clothes to dry in the sun.
• Close Off Unused Rooms - No use wasting energy conditioning rooms that you're not in on a regular basis.

On really hot nights, take advantage of evaporative cooling and mist your sheet with water. As it evaporates, it will get quite cool. Take care not to soak the sheet or you will end up clammy and uncomfortable!

Also look to reduce air infiltration through (and around) windows and doors. Make sure your roof and walls are adequately insulated.