This is similar, but acts more like an evaporative cooler ... very portable and perhaps backpackable as well. [Figjam] took a 5 gallon bucket, wrapped the inside with two layers of swamp cooler ...

Swamp coolers “rely on the flow of air through ... in a window to heat a specific room in your home, and small, portable evaporative coolers on wheels are now available. On the other hand ...