People with cardiovascular conditions at risk in heat: Heart and Stroke Foundation

The Heart and Stroke Foundation says the heat wave hitting Central Canada can be especially dangerous for people with cardiovascular conditions. 

The foundation says extreme heat puts more strain on the heart as it works to get more blood to the skin's surface as the body sweats to regulate its core temperature. 

It says dehydration is a significant risk and people should drink water frequently throughout the day. 

The foundation recommends staying out of the sun during the peak hours of 11 a.m. and 3 p.m. and to consider visiting libraries, malls or community cooling spaces if people don't have air conditioning at home. 

It says people should watch for signs of dehydration, including thirst, dark yellow urine, tiredness, dizziness or confusion. 

The foundation says people taking some heart and high blood pressure medications — including diuretics, ACE inhibitors and calcium channel blockers — need to be extra vigilant about staying hydrated.

It says one of the most dangerous heat effects is heat stroke, a medical emergency when the body can no longer regulate its temperature. 

Symptoms of heat stroke can include hot, dry skin that isn't sweaty, confusion or agitation, dizziness or fainting, a fast heart rate, vomiting or diarrhea and headache. 

If you suspect someone is suffering from heat stroke, call 911 and move them to a cool area.  Drenching the skin with cool water, fanning and ice packs can be useful while waiting for help to arrive. 

The Heart and Stroke Foundation says that despite its name, heat stroke is not the same thing as having a stroke, which is when blood stops flowing to part of the brain. 

This report by The Canadian Press was first published July 14, 2026.

Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.

By Nicole Ireland | Copyright 2026, The Canadian Press. All rights reserved.