How Heat Affects the Brain: What Scientists Have Discovered

Extreme heat has long been recognized as a factor affecting physical health, but its impact on the brain remains far less understood. Many have noticed that in intense heat, it becomes harder to concentrate, thoughts feel sluggish, and irritability rises. Scientists confirm: these are not just subjective sensations but real changes in brain function.

Cognitive psychologist Katherine Thompson from Liverpool Hope University is studying firefighters to understand how heat affects cognitive performance. In controlled experiments, participants exposed to high temperatures for 15 minutes struggled with focus and attention control. However, after 20 minutes of cooling, their performance returned to normal.

The challenge is that these findings come from controlled settings, not real-world heatwaves that persist for days. Thompson notes that conducting large-scale research under such conditions is extremely difficult—it requires rapidly deploying tests to thousands of people just before a heatwave hits. It remains unknown how long the effects of prolonged high temperatures on the brain may last.

Other post-event studies suggest that heat poses a greater threat to individuals with mental health disorders. For them, the consequences can be far more severe than for healthy people. Scientists continue exploring this issue to better understand heat’s mechanisms on the brain and develop guidelines for protecting health amid climate change.