If you don’t live in Hokkaido, Japanese summers are hot and humid! A good way to stay cool, other than staying in a confined room where air-conditioned air is piped out from a room cooler, is to use a uchiwa. It only takes just a little muscle to keep a constant breeze and recently there are highly functional ones that will help send cool air your way!
Stainless Steel type, put it in the Freezer!