Why do we think less clearly in the heat — and argue more often?

I am writing this at the beginning of a scorching August, so I do not need to prove anything: each of us knows how the mind works in an overheated room. More slowly. For shorter periods. With breaks to look for anything cold.

I said I would write about thermal comfort — and it deliberately arrives during the heat, because this is the only time of year when we all believe the science immediately.

And the science says this: temperature is not a matter of comfort, but a condition for functioning. The Healthy Buildings team at Harvard University included thermal health among the nine foundations of a healthy building — alongside air, light and acoustics, which I have already written about. The body maintains a constant core temperature and pays for every degree of deviation with energy. The same energy we meant to spend on thinking, patience and good decisions. That is why, in an overheated room, we argue more easily and work less well — it is not character, it is thermodynamics.

And one more thing that is discussed less often: “too cold” costs exactly the same. Air conditioning set too aggressively is also a deviation — only in the other direction.

What can be done without renovating? Cover the windows before the sun comes in, not once it is already inside — the difference is surprisingly large. Create a through-draught in the morning and evening; keep the house closed during the day. Position a fan so that it moves the air around the body, not beneath the ceiling. And in winter: warm feet and a cool head work better than the other way round.

Today’s question: which room in your home is the hardest to bear in summer — and is that, by any chance, where you try to work?

Next Thursday: humidity. The quietest resident a home can have.

*Source: Harvard T.H. Chan School of Public Health — Healthy Buildings Program (Dr Joseph Allen), “9 Foundations of a Healthy Building” — thermal health as one of the nine foundations.

*Illustration: AI visualisation