Dresser says the evidence suggests that heat can influence us in sometimes indiscernible ways. “All of these [studies] seem to point to a reduced ability to think clearly and quickly and efficiently when the body is too hot,” he says.
There’s also research to suggest that heat can make you moodier or irritated, in part, perhaps, by raising cortisol levels, and inducing a stress response.
Because they’re effecfively measuring the change in the students’ performance in the STROOP and ADD tests before and after a heat wave, baseline factors such as wealth and income should be controlled for.
They note in the results that in the initial tests there was no significant difference between both groups’ results.