In the previous year, we witnessed the hottest temperatures ever recorded globally, with Canada experiencing a rise in temperatures that is twice the worldwide average. Notably, your brain has a significant role in helping you manage heat waves, but it requires assistance as temperatures continue to rise.
Your body’s temperature regulator
Located deep within your brain is the hypothalamus, which maintains your internal body temperature at a level that is just right—not too hot, not too cold.
“The hypothalamus is responsible for regulating body temperature by interpreting signals from thermoreceptors distributed throughout the body,” states emergency medicine physician, Dr. Arie Francis. “Based on this information, it activates various mechanisms to adjust body temperature.”
For example, if the brain detects an increase in temperature, it may trigger the body to sweat, which then evaporates and cools the skin. Conversely, if it perceives cold conditions, it prompts shivering to elevate core temperature.
However, there are limits to how effectively the hypothalamus can function, particularly when exposed to excessive heat.
The effects of heat on your brain
Your brain puts in extra effort to help maintain your body temperature, but excessive heat can also impact its function. “When subjected to high temperatures, the body prioritizes cooling itself, which can result in reduced blood flow to the brain,” warns Dr. Sean Ormond.
This decreased blood flow means that the brain receives fewer nutrients and less oxygen, adversely affecting mental health and cognitive abilities. “Consequently, many individuals may experience confusion and disorientation,” notes Dr. David Tang, an emergency physician specializing in sports and exercise medicine.
During last year’s devastating heat wave in Europe, several hikers, despite clear trails, went missing; some experts suspect the heat may have led these previously healthy people to become disoriented and make errant decisions.
Prolonged exposure to heat without intervention can have severe consequences. “Extended heat exposure can cause the brain to swell,” Dr. Ormond cautions. “This escalation poses serious risks—heat exhaustion and heat stroke could occur, and individuals with existing conditions like migraines or chronic pain may see their symptoms exacerbate.”
Fortunately, there are proactive steps you can take to support your hypothalamus and safeguard your brain and body.
Protecting your brain from heat
“The optimal time to ready yourself for extreme heat is before stepping outside,” suggests family nurse practitioner, Jung Baccam.
Monitor the weather
Consult reliable sources such as Environment Canada to check both the weather forecast and the current heat index, paying attention to more than just the temperature itself.
Dr. Francis emphasizes that high humidity levels and extended sun exposure significantly increase the risk of heat-related illnesses. On excessively hot and humid days, it’s best to limit outdoor activities between 10 am and 4 pm, when the heat peaks.
Dress for heat protection
“Choose loose, light-colored clothing, along with a hat and sunglasses, and don’t forget sunscreen,” advises Baccam.
Utilizing mineral-based sunscreens can aid in maintaining a cooler body temperature by reflecting sunlight. This is particularly important as ultraviolet rays from the sun can reduce blood circulation, a vital factor for effective temperature regulation.
Consider a midday break
There’s a reason siestas are popular in hotter climates. “Whenever feasible, take breaks in shaded areas or air-conditioned environments,” suggests Ormond, who also recommends the regular use of cooling towels or misting sprays.
Help your body and mind recuperate
“After exposure to intense heat, it’s crucial to rehydrate,” Ormond emphasizes. On especially sweltering days, just drinking water might not suffice. “A cool—not freezing—shower can help gradually lower your body temperature,” he suggests, “and resting in a cool, dark space is essential; your brain deserves time to recoup.”
Applying a cool cloth to pulse points, such as your neck and armpits, can facilitate quicker cooling due to the higher concentration of blood vessels in these areas.
A proactive approach to an increasingly warm future
“Heat waves are increasingly normal,” says Ormond, stressing the importance of understanding their effects on health. He asserts that governmental investment in cooling infrastructure—like green roofs and tree planting—is essential, but individuals must also take responsibility.
“We need to cultivate habits that keep us safe,” he concludes. “Heat can pose serious risks; however, by paying attention to our bodies and taking necessary precautions, we can remain safe, even on the hottest of days.”
This article originally appeared in the June 2025 edition of Intomodel magazine.
