How to work in the sun without it going to your head
As temperatures soar Luke Mintz looks at how the heat affects your brain and your ability to multitask
With temperatures set to reach 34C in some parts this week, office workers across the land are deciding to take advantage of their new working-from-home lifestyle by setting up in their back garden, or local park. All you need is a laptop, sturdy Wi-fi connection, and maybe a “hood” (a mini tent that allows you to see your screen in direct sunlight) and, voila, you have your own outdoor office.
But might your work suffer from large periods of time spent in direct sunlight during a heatwave? That was the conclusion of a study published this week in the Scientific Reports journal. Researchers in Denmark and Greece examined the brain function of eight healthy, active men aged between 27 and 41, who were asked to complete a series of maths and logic tasks. During some of the tasks, they were exposed to heat lamps positioned to shine on to their lower bodies and back. During others, the heat radiated on to the top and side of their heads.
The men scored lowest when the heat lamps were shining on their heads, researchers found, suggesting that “direct exposure to sunlight – especially to the head – impairs motor and cognitive performance”, according to lead researcher Prof Lars Nybo, of the University of Copenhagen.
The idea that prolonged exposure to the sun might diminish brain function is one that has been gaining traction among scientists for some time.
Working in high temperatures has long been known to cause hyperthermia, a rise in internal body temperature, which can trigger physical exhaustion. And at the extreme end, those who experience heat stroke are known to suffer from severe confusion. But some researchers are coming around to the idea that hot weather might also affect your intellectual faculties in a far more subtle way – one that you might not even notice happening – by slowing your brain’s processing speed, making it harder to make good decisions.
One review, published in 2003 in the International Journal of Hyperthermia, found that a fairly hot day during the average British summer can easily impair brain capacity. The most severely affected activities were “vigilance tasks” such as driving, or scanning through a long document, or video clip. The ability to multitask is also badly affected by the heat, they found. On the other hand, “mental transformation tasks”, such as working with shapes as designers or engineers might do, are less vulnerable to heat stress, as are “reaction time tasks” – for instance, recalling a statistic on the spot during a Zoom meeting.
Dr Federico Formenti, a physiologist at King’s College London, says that those working outside this week should keep in mind that the impact of heat on brain function is much starker in those who are moving around.
Even exercise as minor as walking around your garden while you take on a phone call could make a difference. “It is likely that your core body temperature could increase marginally, and that could have a noticeable effect on your intellectual capacity for a period of time,” he explains. But he thinks that the concentration of sunlight needed to have this effect is only reached in Britain on the very hottest handful of days each year.
The 2003 study named 30C as the danger point – which many parts of the country are expected to exceed this week. The Copenhagen study, on the other hand, pinpointed 38.5C – unlikely in the UK, although some back gardens can create sun traps that boost temperatures by a few degrees.
So grab your laptop hood, slap on the factor 50 and enjoy your garden office while it lasts – just don’t expect it to land you a promotion any time soon.