I've read on many sites about using
bubble wrap to insulate windows. Some suggest making a metal frame and attaching the bubble wrap before inserting inside the window frame. Others recommend cutting the bubble wrap to the size of the window (large bubbles work best)
spraying the window with water and attaching the bubble wrap with the bubbles facing the window. It has been reported that it sometimes makes a difference as much as 15 degrees to the inside temperature.
