But with an electric fan, there's something you can do before bedtime that could cool the room by several degrees. It involves pointing the fan out of an open window in one room, while opening doors and windows in other parts of the home. This works best when the temperature outside is lower than indoors, and when the fan is placed about two feet from the open window. It's also a good idea to try and stop heat from entering your home in the first place. Then, when outdoor temperatures drop later in the day, open windows and use fans to circulate cooler air and flush out that built-up heat.