If asked what they can do to protect their memory and make their brain work well, most people think of the kinds of food they eat, nutritional supplements they take, exercise they get, and maybe controlling the stress in their lives. But very few think of a common item in their house that might play a part in boosting their brain power.
That item is called a thermostat. Yup… the box on the wall that controls how warm your house gets in winter, and how cool in the summer (assuming you have central air conditioning). It turns out that the temperature of the air around you plays a role in how well you think… impacting how well your memory functions, as well as how well you do on projects that require focused mental effort.
Research has found that an indoor temperature that is either too hot or too cold impairs your intellectual abilities. For example, people who don’t have or don’t use air conditioning during the summer, don’t do as well on tests of mental function as people who stay comfortably cool using air conditioning.
During a heat wave, Harvard researchers found the people who lived in a dorm without air conditioning had significantly more difficulty with cognitive tests than the people who lived in cool temperature-controlled buildings. The people who lived without air conditioning in that heat wave did worse in five measures of cognitive function:
their reaction times,
their working memory,
their ability to focus on what they were doing, and
their learning ability.
Surprisingly, the biggest difference in mental functioning between those in air-conditioned living quarters and those without air-conditioning, occurred AFTER the heat wave began to subside. The researchers concluded this was due to the fact that the indoor temperatures in the non-air-conditioned spaces remained significantly higher than in the air-conditioned spaces, because the non-air conditioned buildings were built to stay warm in the winter. But they are not designed to cool off quickly in the summer.
A study done at the University of Pittsburgh found that if you do an exercise strenuous enough to make you sweat heavily, your mental performance also suffers from that. But the drop in intellectual performance didn’t occur until an hour or two after their exercise session. This may well mean that it’s not a good idea to exercise heavily too close to the time of a demanding mental task.
Cold temperatures also take a toll. Kent State University researchers found men subjected to colder temperatures during various times of the day — down to about 50 degrees — and then warmed up, had difficulty performing well on mental tasks both while they were chilled and after they warmed up.
The researchers believe that when you are chilly, your brain might actually become even colder than the rest of your body. Plus, there’s the possibility that cooler temperatures might slow down the blood supply to your brain as the brain’s blood vessels constrict from the cold, and that slowdown could make it harder to maintain concentration.
Obviously, the easiest way to deal with the impact on mental function due to being too hot or too cold is to keep the temperature in your indoor environment as comfortable as possible. (Remember for sleeping though, all the experts say a cooler room temperature is needed for better sleep—about from 65 to 68 is often recommended.) And, if you do get hot enough to sweat, or cold enough to feel chilled, you might want to put off any significant mental tasks for at least a few hours after the end of the too-hot or too-cold event.
Two other ways experts say you can counter the effects of the too-cold or too-hot indoor space, is with tyrosine supplements or caffeine. Tyrosine is an amino acid that has been found to “help maintain cognitive function in extreme environmental conditions”. One study found that tyrosine protects the brain when it’s exposed to hot temperatures by maintaining the function of the neurotransmitters dopamine and norepinephrine. Other tests have found a similar benefit in cold temperatures from tyrosine.
Caffeine has been reported by researchers to support mental powers during cold temperatures. A test conducted on Navy Seals found that caffeine improves “cognitive function, including vigilance, learning, memory, and mood state”. The test on the Seals found 200 mg of caffeine (the amount in a 12-oz cup of coffee) was enough to do the trick. Caffeine from either coffee or tea can work. We haven’t seen any studies on caffeine being used to counter mental challenges due to hot temperatures.
So, pay attention to your thermostat!