What to cover windows with to help stop heat getting out?

Dean, you can get shrinkable window covering kits at Home Depot, Lowes, hardware stores, etc. They come with double sided tape and very large pieces of plastic wrap. After you attach the plastic by sticking the tape all around the edges of the windows, you heat the plastic with a hair drier and it stretches as tight as a drum.

I used these for several years before I replaced the windows in my older home and it makes a huge difference and looks nearly invisible. They seal air tight and you can see the plastic bow in and out with changes in the wind.

I have used kits by 3M and Manco. The 3M kits are more expensive, but the tape releases easier when you want to take them off in the warm weather.

Dennis

What I do is put up internal shutters, 1" styrofoam, at night. The house feels instantly warmer.

That last part can be important. When that sticky tape spends a few months baking in the sun, it ends up sticking a bit too well. I used to use the stuff and I've pulled off layers of paint and even some chunks of joint compound upon removal in the spring.

DJ