Not literally, but just about.
In the next year or two we’ll be replacing the old, crappy, single-paned aluminum windows in our house. For this winter, though, we’re covering them over with a layer of window insulation wrap. Available at hardware and home improvement stores (aisle B6, at weatherstripping, in the Eugene Jerry’s), this is a cheap way to keep some of the cold out and the heat in.
Window kits cost less than $10 — and that’s for the big ones, up to 210 inches long — for large windows, or perfect for cutting up to cover multiple smaller windows. There’ll be some double-stick tape, just apply that around the window (inside or outside, though inside is easier) and apply the wrap from one top corner to the other, one side at a time.
The last part is the best: Get out a hair dryer, put it on its hottest setting, and blow it over the wrap. This removes wrinkles, stretching the wrap so it’s pretty much invisible.
We’ve done a few windows in the house so far, and I can already tell a difference. It will still be better once we replace all the windows, but we can get pretty close just by spending about $30 and doing some blow-drying.