To the nosey one track minded, who think that I've put foil on the windows , due to their cannabis habits !!! However it's in fact to keep cool !!! Again, "thank you", for the nosey defamatory comments...If you put foil on the window pane, of where you get the most penetration of heat, you'll find it cools the room down, very quickly & on the shaded side of the property, open up a window... (obviously,.for security, close when out)...Plus, when covering just one pane, it's going to be less of a risk of "malicious commination raids" via stirring nosey neighbours, who with council staff, have made all sort of ridiculous allegations !!! xxx "Snouts out" !!! xxx Beloud