Bubble Wrap On Windows. Using bubble wrap on your windows is the easiest method, by far, to reduce heat loss and lower heating bills (and if you've ever used one of those indoor temperature sensors that you aim at the walls and windows, you will know how the temperature drops rapidly when the device is aimed at windows). Did you pop the bubble wrap in childhood?
Heat Shrink Plastic Kits for Windows. Is it time to toss away your caulking gun and invest in a few dollars' worths of stretchy, clingy. You will need a spray bottle How Well Does Bubble Wrap Insulate.
While we normally associate bubble wrap with moving or packing fragile items so they won't break, there's insulating magic in bubble wrap.
Saran Wrap (and other brands of plastic wrap) come in long sheets.
Air, particularly air in a confined space, is a good insulator because the air inside the space tends to resist temperature changes. I would much rather get a gift wrapped in bubbles than those horrible packing peanuts that go everywhere. This is a completely pointless little bubblewrap popping application.