“Cardboard Cooler” with cooling function using frozen plastic bottles.

I thought it was ridiculous to make your own air conditioner out of cheap materials, but apparently it’s actually quite cool.

However, the author of the article says that “the wind smells a little like metal.”

The article is in Japanese, but for details, please refer to the link below.

大人も楽しい自由研究(6) 【結構涼しい】凍らせたペットボトルで『ダンボールクーラー』を作ってみた | マイナビニュース