Insulating a room in the summertime with rola folie de aluminiu can help keep sunlight out of the room and lower temperatures. Completely cover all windows with aluminum foil and secure it with a heavy-duty tape such as duct tape. The shiny surface will reflect the sunlight's rays. You can also insulate cold food when it will be near the sun. Wrapping a cold soda can, for instance, with aluminum foil will keep it chilled. Adding a layer of bubble paper between the aluminum foil and soda can will keep it cooler for longer.
If you would like to insulate something in a dark place, such as lunch box, another material such as cotton or paper could work just as well as aluminum foil. As a matter of fact, cotton is regularly used for insulation, as it is environmentally friendly. Because aluminum foil reflects light, when it is in a dark place, there is no light for it to reflect, so it will work similarly to other materials.