Summer heat and young brains


The fact that schools and higher learning institutions close for the summer holidays might not be based on neuroscience but is nevertheless wise. It has to do with the effect of heat on our brains. 

I’m sure we can all relate to the experience of not being able to focus and cope with mental work in extreme heat.  The same can be said for children, struggling in a hot classroom. 

A recent study finds a link between heat and lower academic achievement.  High school students who were tested during hotter years had lower scores compared to their test performance after a cooler year. Another study concerned university students who were given two tests a day of basic addition and subtraction, cognitive speed, memory, attention and processing speed for 12 consecutive days during a particularly hot spell. Those students who lived in air-conditioned buildings scored significantly higher than those who did not.  Yet another researcher[1]wrote that taking an exam on a day where the temperature reaches 32 degrees Centigrade leads to a 10.9% lower likelihood of passing a particular subject (e.g. Algebra). 

So our hot South African summers cause some brain drain and possibly our youngsters could benefit from schools staying closed during January and February, the hottest months of the year.  Of course, air conditioning seems to offset the damaging impacts of heat on academic achievement but we know how expensive it is to install and run air conditioners in   schools. We also know that air conditioners release carbon dioxide into the atmosphere which is not good for our already struggling environment. 

But summer heat can cause physical problems for children as well. It’s important to remember children are at high risk for heat-related illnesses, as their bodies heat up 3-5 times faster than those of adults. When the weather is extremely hot and humid, the body’s ability to cool itself down is compromised, and both adults and children are at risk if the temperature rises above 32 degrees Centigrade.

Dehydration is a major concern and it should be remembered that often children don’t feel thirsty when they are engaging in physical activities out of doors.

  • Before outdoor physical activities, children should drink freely.During activities, they should have water available and take a break to drink every 20 minutes.
  • Sports practices and games played in the heat should be shortened and there should be more frequent water breaks.
  • Clothing should be light-coloured and lightweight. Limit clothing to one layer of absorbent material to help the evaporation of sweat. If their shirts become sweaty, they should change to dry clothing.
  • Children complaining of feeling dizzy, lightheaded or nauseous should be allowed to move into a cooler environment.

There is no doubt that heat and dehydration can make children sick.  Apart from dehydration, children can also suffer from heat exhaustion, heat cramps and heat strokes.

Your child may not tell you if they’re feeling bad, so it’s critical to recognize the signs and symptoms of these heat-related illnesses in order to take proper action and prevent further injury.

If your child develops any of the following symptoms, it might be wise to call your pediatrician immediately:

  • Feeling faint
  • Extreme tiredness (e.g. unusually sleepy, drowsy or hard to arouse)
  • Headache
  • Fever
  • Intense thirst
  • Not urinating for many hours
  • Nausea
  • Vomiting
  • Breathing faster or deeper than normal
  • Skin numbness or tingling
  • Muscle aches
  • Muscles spasms.

With the long summer holidays looming every closer, plan to protect your children from the heat by playing outside in the early mornings and late afternoons (apart from swimming).  Children may become restless if kept indoors for too long so make sure you have entertainment planned in the form of indoor games and activities. 

But don’t forget to limit the amount of screen time!

 [1]R. Jisung Park, Assistant Professor at the University of California, Los Angeles.

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