Hang curtains or drapes to block light during the hottest hours. Curtains cover the window only and drapes go all the way down to the floor. Both are effective, but drapes are better at blocking light. Go with closed-weave, heavy fabrics in light, opaque colors, and hang the drapery as close to the window as possible. Drapes and curtains with white plastic backings may reflect even more light Keep drapes closed during the hottest hours of the day. Typically, 10am–4pm are the hottest hours, but it depends on where you live. Try vertical or horizontal blinds for a cost-efficient way to reduce heat. Slat-type window blinds are an affordable solution and allow you to control glare, light, and heat by simply adjusting the slats. Look for highly reflective blinds in a style you like and keep them tightly closed during the hottest part of the day. If you have horizontal blinds, consider painting your interior walls a light color. Horizontal slats reflect sunlight onto the ceiling and light colors diffuse that light effectively without creating a lot of heat or glare. Blinds aren't as effective as drapery at blocking light and heat, but being able to adjust them is a nice plus. Blinds with reflective finishes on the outward-facing side are the best choice. Install roller or roman shades indoors for an inexpensive option. These shades are easy to install and won’t put a huge dent in your wallet. Typically, you attach a roller bar at the top of the window and lower the shades with an attached cord. Roman shades are fairly similar but they’re made of fabric. Heavier fabrics are the most effective, so look for tight, thick weaves. Opaque roller shades are the most effective option, but only when they're fully drawn. On the downside, they block light and restrict airflow.