Are there any inexpensive ways to block the heat from your windows?

I used those tinfoil-like emergency blankets one hot summer. The shine reflected the heat back

The big box stores sell a film which can be applied to the inside of your windows. Many are deigned to cut down the UV rays, and you can still see through it. Otherwise, many of the companies who apply window film to cars will offer a home service too.

Try Blackout Curtains. Walmart sells Eclipse Black out curtains. The panels come in several colors and run about $9. @. Hang the curtains and keep the window closed. JHaymon

Try Blackout Curtains. Panels cost about $9.00 @. Eclipse is a good brand. They come in several colors. Once hung keep Windows closed. JHaymon

We put bubble wrap on our windows to keep the cold out in winter in a porch where there is no heat except for a space heater. You might try that with heat. We used the small bubble wrap. Surprising how you can see thru.

If they are older, single pane windows make sure they are glazed and sealed well. You will still get heat through, but it will stop air flow. Insulated, lined curtains can help, they are about $20 a panel though, depending on how big your window is. You can also get those clear plastic window insulating kits for about $8 each, they will do several windows, each. We finally had to replace windows to stop heat coming in, it was getting so hot when the direct sun hit that it was melting our blinds, and I don't mean the super thin, plastic ones.

I've used black out drapes and thermal drapes for years. If you don't have double paned windows you can use the window vinyl rolls that they sell at the hardware store that can reflect the heat. They are not hard to install. Usually just water bottle, utility knife and a squeegee.

Black out drapes are the way to go. It will extremely reduce the amount of heat coming in.