Why heat makes you stupid
There’s a specific kind of summer brain that feels like trying to do calculus inside a hairdryer.
You’re technically conscious, but only just.
You go to the fridge and forget why, aside form to stick your face in it.
You reread the same sentence four times and still can’t tell if it's about a person, a puddle, or an emotional breakdown.
Turns out, it’s not just you.
Science. That relentless killjoy. Science has confirmed what every sunburnt student already knows: hot weather makes your brain a bit useless.
Not permanently.
Just enough to fail an exam or accidentally call your teacher mum.
There’s an actual Harvard study (because if you're going to collapse mentally, you might as well do it with Ivy League validation) where students in non-air-conditioned dorms scored 13.4% lower on cognitive tests during a heatwave.
Thirteen percent. That’s the difference between a smug A* and “I’ll retake it in November.”
Why? Because your body prioritises survival over IQ.
When your core temperature rises, it reroutes blood away from your brain to your skin to help cool you down. Great for not dying. Terrible for algebra.
So you sit there, glazed and overcooked, typing “defiantly” instead of “definitely” and leaving it there. The sentence makes no sense. Neither do you.
So... what’s the fix?
Apparently, if you’re physically fit, you have an advantage.
Annoying, I know.
Fitter bodies act like portable air-conditioning units. They sweat more efficiently, regulate core temperature better, and their brains — those high-maintenance divas — cope slightly better.
A 2021 paper in Temperature (yes, it’s a real journal) found that heat-acclimated, aerobically fit individuals had better reaction times and working memory under thermal stress than their sedentary counterparts.
Translation: They’re still sweating, but they're doing it with a brain that still knows long division.
This does not mean fit people are smarter in summer.
It just means they’re less dumb than the rest of us, while we melt like forgotten lollipops on a car seat.
But before you sprint to the treadmill, remember: exercise adaptation takes weeks. So unless you’ve already been doing HIIT in the sun like some kind of cardiovascular masochist, this isn’t your fast-track to clarity.
That said, running does help build heat resilience. It also gives you stronger legs and the moral superiority to wear Lycra on public transport. So. Swings and roundabouts.
🔥 How to Outsmart the Heat (Barely)
- Hydrate — not just iced coffee (though absolutely), actual water. Your brain is 75% water and 100% drama.
- Work early — morning brains in a heatwave are 200% more reliable than afternoon ones, according to me (and actual research).
- Fans, shade, and Victorian-era survival tactics — draw the curtains, drape yourself artfully, and wait for the scandal of fainting before noon.
- Breaks — your brain fries faster in heat. Work in short bursts. Think microwave popcorn, not slow roast.
- Cool like a lizard — cold wrists, chilled neck, possibly a head dunk in a paddling pool. Zero shame.
If you’re feeling foggy, irritable, and unable to spell your own name when it’s 34°C — you’re not lazy.
You’re hot.
Not in the Instagram-sunset-selfie sense — in the “your neurons are misfiring and your brain’s internal air-conditioning has failed” sense.
Cognitive performance plummets in heat.
Fitter people suffer less, but nobody’s immune.
And if you're currently melting in a classroom, office, or your least favourite exam hall, know this: you're in a long, noble tradition of brilliant minds being outwitted by summer.
So, drink some water. Sit near a fan. Lower your expectations.
And forgive yourself for not being Einstein in a heatwave — he probably just napped under a tree and called it theoretical work.
Nici
P.S.
This article took twice as long to write because my laptop overheated and so did my brain. Solidarity.
If you know someone else whose IQ is wilting in the sun, send them this. It's basically SPF for their sanity.
