Open windows and sliding doors during the morning and evening to let in cool air. Monitor your thermostat, and close the windows and doors once the daytime temperature exceeds a comfortable level. To help keep the heat out, block the sunlight by drawing the curtains. If you don't have any, you can purchase a decent pair of curtains for $20 to $70.

ANdrew D. Brosig/The Daily Sentinel/AP/File
Volunteer Trina Wyrick paints exterior window casings during a Women Build Day event in this May 2012 file photo, at a Habitat for Humanity house under construction on Ritchie Street in Nacogdoches, Texas. Putting curtains over windows is a good way to beat the heat in your home.