In hot weather like the kind we’ve seen this summer, fans are everywhere: They’re inexpensive tools that help us feel better in the heat.

The key word here is “feel.” In temperatures of around 90 degrees and higher, which much of the country has been experiencing this summer, fans do very little to help us beyond tricking our brains into believing we’re not entering heat exhaustion. In extreme heat, fans may paradoxically make you hotter.

(Text from the report.)