A DIY evaporative cooler or mist fan that blows water droplets onto your skin to help cool you down.
If you’ve ever walked out of a shower and then stepped in front of a fan, you know how cold it can be. This is a similar idea. The water is blown onto your skin and it evaporates as the fan blows over you, cooling you down quickly.
The downside, when using this misting fan indoors is that everything around it will get wet and the room humidity will increase.
When using this outdoors, there’s really no downside and it’s an effective way of cooling people down.