Can some medications impact your ability to handle extreme heat? What to know

Medical professionals say certain medications can have an impact on how the body regulates heat and to be aware of your risk factors when high temperatures are expected.

Canadians are sweltering under the heat wave in Ontario and parts of Quebec, and for those taking certain medications, precaution is needed as the thermometre soars.

The two provinces are seeing the humidex reach the low to mid-40s on Wednesday with the heat expected to stay to the end of the week, and medical experts like Dr. Samantha Green say those on some medications should be aware that what they’re taking could impact their ability to handle that extreme heat.

“Some of those medications directly interfere with the hypothalamus, which is the body’s thermostat, and the way that the body kind of co-ordinates normal thermo-regulation, and some of those medications interfere with some of the ways that our body is able to cool itself,” Green, a family physician, told Global News.

According to Green, that part of the brain tells the lungs to start breathing faster and the heart to start beating at a higher rate. It causes the blood to be closer to the surface of the skin and helps the body lose some of its heat through radiant cooling. In addition, the body will also sweat, which allows people to lose further body heat by evaporation.

According to Health Canada, medication that can impact the hypothalamus, heat perception, cardiac output, sweat rate, body hydration, renal function and electrolyte status can cause someone to be at a higher risk of heat illness.

Some examples of medications that can have an impact on the body during heat are ACE inhibitors and beta blockers used to treat heart-related problems, diuretics, antidepressants, anti-seizure medication, and even antihistamines, which can reduce sweating.

Medications like antidepressants and anti-psychotics can also have an impact on the hypothalamus. Diuretics, which can be used to treat blood pressure, can interfere with normal sweating because the body can end up slightly dehydrated.

“You don’t get as thirsty or don’t feel the sensation of thirst as you would have if you weren’t on that medication, so you’re not necessarily making sure that you’re drinking as much because you’re not feeling that sensation of thirst,” Ontario pharmacist Kristen Watt told Global News.