Multi-Day Heat Warning Issued for South East Health Unit Region

Environment Canada has issued a warning for the entirety of the South East Health Unit (SEHU) area for a multi-day heat event that began on Sunday, June 22. For specific information about the alerts in your area, please visit Environment Canada’s Weather Information page.  

Conditions during high heat and humidity have the potential to cause dehydration and heat illnesses, which include heat stroke, heat exhaustion, heat fainting, heat edema (swelling of hands, feet and ankles), heat rash and heat cramps (muscle cramps). 

Watch for symptoms of heat illness, which include: 

• Dizziness or fainting
• Nausea or vomiting
• Headache
• Rapid breathing and heartbeat
• Extreme thirst
• Decreased urination with unusually dark yellow urine 

 If you experience any of these symptoms during extreme heat, immediately move to a cool place and drink liquids. Water is best. 

A heat warning is issued by Environment Canada when the forecasted maximum temperature is expected to be greater than or equal to 31°C and the lowest night-time temperature is anticipated to be at or above 20°C for a period of two days or longer. A warning will also be issued if the anticipated humidex is 40°C or warmer for a period of two days or longer. 

Humidex values describe how the hot and humid weather feels to the average person. It combines the temperature and humidity readings into one number to reflect the perceived temperature. The higher the humidex, the harder it is for perspiration to evaporate to cool the body. 

During heat events everyone is at risk; however, the health risks are greatest for: 

• Infants and young children
• People who are pregnant
• Older adults
• People who live alone
• People with chronic medical conditions (for example, heart disease, respiratory conditions, those who are overweight or who have diabetes) or mental illnesses (for example, schizophrenia, depression, dementia)
• People on certain types of medications (for example: high blood pressure medications, medications for mental illnesses, etc.)
• People experiencing homelessness, those who are underhoused or encounter other challenges in accessing cool spaces
• People with limited mobility
• People who exercise vigorously outdoors (play sports, cyclists, gardeners)
• Outdoor workers (depending upon length of time and exertion levels)
• People who work in places where heat is emitted through industrial processes (for example, foundries, bakeries, dry cleaners) 

If you or a loved one is at an increased risk for heat-related health risks, SEHU recommends designating someone, a friend or neighbour, to do a wellness check on yourself or them throughout the duration of a heat event.  

Being prepared is key to protecting communities from negative health impacts due to heat. Heat illnesses are preventable. SEHU recommends taking the following actions to stay cool: 

• Drink plenty of cool liquids, especially water, before feeling thirsty.
• Avoid direct sun exposure, for example, sit under a tree, wear a wide-brimmed, breathable hat, or use an umbrella.
• Prepare meals that don’t need to be cooked in your oven and block out sun by closing awnings, curtains or blinds during the day.
• Take breaks from the heat by spending a few hours in a cool place; take cool showers.
• Reschedule strenuous outdoor activity or plan outdoor activities during cooler parts of the day.
• Wear loose-fitting, light-coloured clothing made of breathable fabric.
• Prepare a basement or cooler part of your home, for occupancy throughout and during the heat event.  
• Block the sun out by closing awnings, curtains, or blinds during the day, especially on the westerly side of the home or building. 
• Never leave people or pets in your care inside a parked vehicle or in direct sunlight. 

SEHU encourages everyone to check on their neighbours, friends and family members, especially those who are chronically ill, and those at higher risk, to make sure that they are cool and hydrated. 

For more information on protective measures during heat events, and for help finding cooling centres in your area, visit: https://healthunit.org/for-professionals/municipal-staff-partners/emergency-planning-response/cooling-centres-in-leeds-grenville-and-lanark/