Temperature and Cognitive Performance: Evidence from Mental Arithmetic Training

With rising average temperatures and extreme heat events becoming more frequent, understanding the ramifications for cognitive performance is essential. I estimate the effect of outside air temperature on performance in mental arithmetic training games. Using data from 31,000 individuals and 1.15 million games played, I analyze frequent engagement in a cognitively challenging task in a non-stressful and familiar environment. I find that, above a threshold of 16.5 ∘ ∘ C, a 1 ∘ ∘ C increase in outside air temperature leads to a performance reduction of 0.13%. The effect is mostly driven by individuals living in relatively cold areas, who are less adapted to hot temperatures.