How to cool down and recognize signs of heat exhaustion

This article was written by Andy Takagi and was published in the Toronto Star on June 18, 2024.

Julian, 2, cools down while his dad, Geoff, and baby brother, Alex, stay out of the splash zone on Monday.

Toronto, get ready for your first heat wave of the year.

With highs of 35 C (and humidex up to 45 C) and nighttime lows of 20 to 23 C, Environment Canada is warning of “excruciating” weather.

In preparation for the impending heat wave, hours at seven pools have been extended, air conditioning and cooling will be provided at roughly 600 facilities across the city and most TTC vehicles will have air conditioning.

Heat-related illnesses can especially affect vulnerable populations, Dr. Samantha Green, a family physician with Unity Health Toronto, explained.

“The greatest risk is remaining inside, in a hot and non-cooled indoor environment,” she said, adding that people should check in on their friends, family and neighbours, especially isolated seniors.

Here’s what to look out for during this week’s heat wave, and how to stay cool.

What are the signs of heat exhaustion and heat stroke?

Heat exhaustion can quickly turn into heat stroke, which has a 50 per cent mortality rate, Green said — meaning half of people who have a heat stroke die.

Heat exhaustion can have “nonspecific symptoms,” Green explained, but can include:

■ generally feeling unwell

■ dizziness

■ headache

■ irritability

■ fatigue

■ thirst

■ nausea

■ heavy sweating

■ decreased urination

Heat exhaustion can quickly turn into heat stroke when the person experiences confusion or becomes unconscious.

“That’s a medical emergency,” Green said, and if you are with someone experiencing a heat stroke, they should call 911 immediately.

Several groups are more susceptible to heat stroke, she said, with Environment Canada warning that older adults, infants and young children, and pregnant people are at greater risk of heat-related illnesses.

People with underlying chronic health conditions (like asthma, chronic obstructive pulmonary disease, heart disease, diabetes, kidney disease or mental health conditions) are especially at risk, she explained.

How to prevent heat stroke

There are steps you can take to prevent heat stroke, according to the Mayo Clinic.

Wearing loose-fitting, lightweight clothing, using sunscreen (at least 15 SPF) to prevent against sunburn, drinking plenty of fluids, getting acclimated if you’re not used to hot weather, and regular rest are all important steps to preventing heat exhaustion and heat stroke.

There are two ways to temper heat exhaustion, Green said: reducing the air temperature or reducing your body temperature.

Taking off any extra layers of clothing, drinking cool water, or applying wet towels or ice to the under arms, groin or back of the head can help to quickly cool the body, she advised. A cool shower can help and cool mist will work if the humidity is below 70 per cent.

It’s also important to avoid physical activity, especially during the hottest hours of the day, and avoiding the use of appliances like ovens that might heat up the air indoors.

Air conditioners and fans can help to cool a room down, although fans will only work in indoor temperatures below 35 C. Beyond that point, fans become ineffective, Green warned.

If, however, you’re without air conditioning, Green advised closing the shades or curtains during the day and opening windows at night. High nighttime temperatures can be a “silent killer,” the World Meteorological Association has warned.

Author: Ray Nakano

Ray is a retired, third generation Japanese Canadian born and raised in Hamilton, Ontario. He resides in Toronto where he worked for the Ontario Government for 28 years. Ray was ordained by Thich Nhat Hanh in 2011 and practises in the Plum Village tradition, supporting sanghas in their mindfulness practice. Ray is very concerned about our climate crisis. He has been actively involved with the ClimateFast group (https://climatefast.ca) for the past 5 years. He works to bring awareness of our climate crisis to others and motivate them to take action. He has created the myclimatechange.home.blog website, for tracking climate-related news articles, reports, and organizations. He has created mobilizecanada.ca to focus on what you can do to address the climate crisis. He is always looking for opportunities to reach out to communities, politicians, and governments to communicate about our climate crisis and what we need to do. He says: “Our world is in dire straits. We have to bend the curve on our heat-trapping pollutants in the next few years if we hope to avoid the most serious impacts of human-caused global warming. Doing nothing is not an option. We must do everything we can to create a livable future for our children, our grandchildren, and all future generations.”