I see, all I found is a piece of cloth you tape around window opening though. I don't think it's doing a great job of insulation, and, paired with an inefficient portable unit, what kind of temperature difference can you get inside vs outside?
Enough to prevent death. When I was growing up we used duct tape and cardboard boxes.
[1] https://www.yahoo.com/news/science/articles/europe-heat-wave...