Necessity is the mother of invention
At the beginning of January, the thermometer did not climb above 2 degrees Celsius on the Island of Lesbos, where several thousand refugees under the worst conditions imaginable waited for their asylum application to be processed. Many are living in simple Igloo tents, which are not even suitable as long-accommodation when the weather is good. Official help comes only very hesitantly or not at all.
Just before Christmas, the volunteers, who have been helping refugees on the Island for months, were able to improve conditions: they sprayed the inside of the tents with a substance similar to expanding foam. The foam gets hard and forms, with air enclosed as small bubbles, an insulating layer similar to polystyrene. That way at least some of the cold remains outside. The fact that also the tent floors are sprayed means that less cold is coming from below. The idea for this action came from wortundtat and the aid organisation also assumed part of the costs.
How exactly the isolation works is shown in the following film of the test run on the Leimberghof in Wuppertal.