People who live in regions of the country where winter brings very cold air, can benefit by insulating their windows. The 3M window film Chicago residents can purchase, is designed to fit over the glass section and the outer edges of the window to create a seal. The seal stops the cold air from outside from getting in through the gaps in the window. This film is easy to apply and can be fitted by using a source of heat such as a blow dryer, to shrink it into place. It is an easy and effective way to stop cold air from entering the house during the winter.