A thermal window insert includes at least two substantially parallel,
substantially transparent sheets of flexible polymer material having a gap
therebetween. The two sheets are bonded together at deformations formed in
at least one of the sheets, and have a size approximately corresponding to
the dimensions of a window opening in a building. A strip of resilient
material is directly bonded to the sheets around the perimeter thereof, so
as to seal the gap between the transparent sheets and to provide a seal
between the window insert and the window opening. The invention is similar
to storm windows, but is of a simpler and less expensive construction, and
is easy to install, remove and store.
