5 surprising things to know about heat and your health
Here’s what UBC public health experts want you to know about keeping safe during the next heat wave.
With researchers finding that summers are lasting longer, getting hotter, and bringing more frequent heat waves across much of the world, now's the time to get cool with the health effects of heat.
We spoke with Drs. Michael Brauer and David McVea (MD’14, PhD’14, MPH’17) from the UBC Faculty of Medicine’s School of Population and Public Health (SPPH) about what you should know about extreme heat and how to keep yourself and your loved ones safe when the mercury is climbing.
1. Hot temperatures impact your brain.
In the heat, your body sends blood to your skin and extremities to cool down. That leaves less blood circulating in your brain, which can affect your cognition and mental health.
“Heat is very stressful to your body, and it has biological effects that can impair your mood and your thinking. It can interrupt your sleep, interactions with friends, and exercise routines—all those things that promote good mental health,” says Dr. McVea, a UBC clinical assistant professor at SPPH and public health physician at the BC Centre for Disease Control.
While people with underlying mental-health conditions, including schizophrenia, substance use disorder, and dementia are particularly vulnerable during heat events, soaring temperatures can impair anyone’s decision-making abilities.
“During heat waves, we see increases not just in road traffic collisions, but also things like drownings, homicides, aggressive behaviour, and suicides,” says Dr. Brauer, a professor at SPPH. “Remember that this is a stress to your body, and you may not be thinking and working as efficiently as you would otherwise. It’s important to take this very seriously.”
2. Some medications make it harder for your body to cool down.
The human body is designed to increase sweating and move blood closer to the skin’s surface in hot temperatures. But some medications can interfere with this process, including antidepressants, cholesterol-lowering drugs, blood-pressure medicines, antipsychotics, as well as medications used to treat Alzheimer’s and Parkinson’s disease.
“Some medications work by removing fluid from the body, which can worsen dehydration and put your kidneys at risk, and some can impair how your body perceives and responds to heat,” explains Dr. McVea.
If you are taking medication, he stresses, it’s important not to make any changes, but to be aware of their side effects. “Many of those medications are very important for people’s health. Talk to a pharmacist or a doctor about what the best strategy is to deal with the heat.”
3. Fans aren’t very effective in high temperatures—and may actually make things worse.
In the absence of air conditioning, sitting in front of a fan can seem like the next best thing. But because it makes sweat evaporate more quickly from your skin, you run the risk of dehydration.
“In very hot indoor temperatures, a fan is not generally safe to use,” cautions Dr. McVea. “It can be helpful to bring in cool air from the outside in the evening, but having a fan blowing on your skin is not recommended. It’s not helping to cool your body off and may actually increase your body temperature.”
He recommends using other strategies, such as cooling yourself off with wet towels, having a cold bath or shower, and using a cold foot bath to manage the heat. And be sure to drink plenty of water.
4. The vast majority of heat-related deaths occur at home.
“The majority of heat-related deaths occur out of hospital, which is what we saw during the 2021 heat dome in BC,” says Dr. Brauer. It’s not that they didn’t make it to the emergency room in time—many were isolated with underlying cognitive issues, physical limitations, and/or mental illness.
“It’s actually quite easy to keep cool. But if you’re already compromised and you don’t have the energy or the ability to recognize you’re in danger, that’s when things can cascade very rapidly,” he says.
The good news, he adds, is that these deaths are preventable, with the right resources and mobilizations in place.
5. There’s one thing you can do to keep yourself and loved ones safe.
It sounds simple, but checking in with your friends and loved ones is the most important thing you can do during a heat event—particularly if they are elderly, pregnant, living with schizophrenia and/or substance use disorder, or living alone without air conditioning.
“Each household, each family, each person living alone should have a hot weather plan. For a family supporting an older loved one living alone, that plan might include checking in by phone, checking in in-person, and then perhaps moving that person to a cooler environment if needed,” says Dr. McVea.
When checking in, says Dr. Brauer, be sure to really assess how they’re doing. “Don’t just ask, ‘Are you okay?’ Make sure they sound as they normally would. If they sound confused at all, that is an early sign to get help.”
Other signs to look out for include headaches, dizziness, nausea, and a rapid, weak pulse, which are signs of heat exhaustion and require cooling measures. A lack of sweating, confusion, slurred speech, seizures, fainting, and a rapid, strong pulse are indications of heat stroke and should trigger a call to 9-1-1.
Find more information on heat safety at:
