This might explain Florida Man.

NPR:

“We found that the students who were in the non-air-conditioned buildings actually had slower reaction times: 13 percent lower performance on basic arithmetic tests, and nearly a 10 percent reduction in the number of correct responses per minute,” Allen explains.

The results, published in PLOS Medicine, may come as a surprise. “I think it’s a little bit akin to the frog in the boiling water,” Allen says. There’s a “slow, steady — largely imperceptible — rise in temperature, and you don’t realize it’s having an impact on you.”