Europe had it hot last summer. I felt for those without access to air conditioning and no way for cooling their homes.
Apart from the physical discomfort, brains suffer badly in the heat, which is why in a warming world, it’s important to know how to avoid the risk of heat stress, heat exhaustion or heat stroke.
You’ve no doubt heard that your brain while comprising only 2% of your body weight consumes 20% of the body’s total energy.
All that thinking is not only hard work, its metabolically draining, meaning it’s vital your noggin is kept supplied with enough oxygen and nutrients to enable it to function normally.
Raising your brain’s temperature even by a degree starts to throw your brain’s cognitive function out of the window, which is especially dangerous for the very young and very old, those living with pre-existing conditions and for those with inadequate resources.
Excessive heat disrupts neuronal function while neurotransmitters such as dopamine, serotonin and epinephrin needed to regulate mood and body temperature are also affected.
Now your brain has to work even harder to try and keep the brain safe and this demands even more resources to achieve this.
Little wonder your mind feels tired when you’re too hot.
What excess heat does to your thinking
A hot brain is unpleasant for you and for those around you.
Not only does it appear harder to think, but you can also become confused and suffer memory challenges. Trying to remember things gets harder because your working memory is shot, while you also get more fatigued, thirstier (and dehydration also affects how well your brain works) and have difficulty staying focused.
Essentially, extreme heat drains your brain.
This is not the best time to be making significant decisions, other than to find a way to cool yourself and your home down.
While hot days are uncomfortable, hot nights make sleep difficult. This compounds your fatigue and makes coping with all that darn heat more difficult. We need a temperate temperature of 17-19 degrees C to fall and stay asleep. But if the night temperature is stuck in the mid-twenty degrees C or above, sleep becomes more fragmented and it’s the poor sleep that’s responsible for worse decision-making, impulsive behaviour the following day.
Prior to air conditioning, the Australian habit of sleeping outside on the veranda where there could be a whisper of breeze to cool things down was the norm for many.
This isn’t so easy if you’re living in a multi-storey flat.
You may have also noticed how hot temperatures lead to hot heads. Individuals get more narky, irritable, intolerant, irrational and prone to violence.
So, what’s the impact of more frequent extreme hot temperatures on cognition overall?
One 8 year study of over 50,000 individuals examined the difference and found that extreme high temperatures (over 32 Degrees C) are associated with increased cognitive decline at hourly, daily and annual levels especially in the elderly.
It’s also recognised that exposure to excess heat predisposes to increased levels of inflammation and interferes with the normal functioning of the immune system, putting individuals at increased risk of infection and progression of chronic disease such as heart disease.
Keeping your cool at work
Workplaces can be oases of coolth enabling you to carry on thinking and stay productive.
Others flock to shopping malls for some welcome window shopping and cool relief.
A Chinese study found that increasing the office temperature led to a diminished ability to do basic math or type. Elsewhere, an American study found that students who slept in warmer dorms compared to the climate-controlled dorms of their counterparts performed more poorly in tests and had slower response times.
Mind you, it’s all relative, of course.
My father slept in a school dorm where the windows were kept open all night every night regardless of the weather. He would tell us tales of waking up in the morning to find snow on his bed. So cooler nights are good to allow our core temperature to drop, enabling better sleep, but you don’t want to be hypothermic either.
The solution to a hot problem.
The solution lies in awareness of the dangers extreme heat brings to us all, at any age, and to seek ways to reduce exposure to excess heat wherever possible.
In lifestyle medicine, we seek to keep people well by focusing on preventing harm and reducing the risk of developing chronic disease.
As our world is getting hotter, this entails ensuring you know how to keep cool with healthy lifestyle choices.
The solutions may seem obvious, but are you following them?
- Keep hydrated
Thirst is a poor indicator of hydration. Take a glass of water to bed with you to drink at night if you wake up or drink first thing on waking. During the day carry water with you all the time to sip on across the day. If you drink coffee or tea in the daytime, try alternating these with water. - Keep your bedroom cool 17-19 degrees
- Cool your skin with wet flannels and cool packs.
These, in combination with a fan, can make a big difference - Wear light breathable clothes
Cotton and linen are best - Good ventilation
Fans, vents, evaporative systems all help - Stay out of the hot sun
It’s not just mad dogs and English men. We all do better cognitively by not working in excess outside temperatures. This should include outside sports, though this message doesn’t always appear to be getting through. When it’s hot, slow down and don’t push yourself into being at risk of becoming heat affected.
If you’re a health practitioner interested in learning more about preventing and mitigating the risk of chronic disease, why not join us at the ASLM Conference in Hobart, November 13-15th, looking at “the Nature of Health.”
We’d love to have your company.
You can find out more about the event here.
