You don’t have to switch on the air conditioner to get a big chill this summer. Block That Sun! When sunlight enters your house, it turns into heat. You’ll keep your house cooler if you reduce solar heat gain by keeping sunlight out. Close the drapes: Line them with light-colored fabric that reflects the sun, and close them during the hottest part of the day. Let them pillow onto the floor to block air movement. Add awnings: Install them on south- and west-facing windows to r