I don't know if that is a joke, but shutter != gutter. A shutter covers the window during hot weather to keep the sun out and keep the building cool, and can be

I don't know if that is a joke, but shutter != gutter. A shutter covers the window during hot weather to keep the sun out and keep the building cool, and can be opened during cooler weather. The relevancy is that unlike air-conditioning they don't consume power or heat the surrounding city.