Ever feel that the arrival of summer sun makes you feel a bit dopey? You wouldn’t be the only one. Soaring temperatures are known for their ability to slow our thought processes, making even everyday tasks seem like a baffling ordeal.

But what is actually happening inside our heads when the heat is on? The explanation appears to lie in the extra work our brain and body have to do to keep us cool.

The brain and body are in constant conversation. When outdoor temperatures change, thermoreceptors which sit near the surface of the skin send signals to the hypothalamus – the brain’s temperature regulation centre.

When things become too hot or cold, the hypothalamus co-ordinates a series of responses to bring body temperature back towards normal (around 37°C). Keeping the core temperature at this level is critical for metabolism, activity of enzymes and many other essential body functions.

Being commander-in-chief of temperature regulation means that the brain becomes rather occupied when having to consistently regulate your temperature.

In hot weather, this means cooling the body down by switching on mechanisms that allow heat to radiate from the surface. This includes diverting blood to........

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