Extreme Heat in Ontario: How to Stay Safe and Understand Your Rights During Dangerous Summer Temperatures

July 22, 2026, Kitchener, Ontario

Posted by: Robert Deutschmann, Personal Injury Lawyer

Ontario's Summers Are Getting Hotter—And More Dangerous

Ontario is no stranger to warm summers, but in recent years, heat waves have become more frequent, more intense and longer lasting. Environment and Climate Change Canada regularly issues Heat Warnings and Extreme Heat Warnings when temperatures and humidity reach levels that pose a significant health risk.

For most people, extreme heat is uncomfortable.

For others, it can be life-threatening.

Every summer, Ontarians are treated in emergency departments for heat exhaustion, heat stroke, dehydration, burns from hot surfaces and other preventable heat-related injuries. Seniors, young children, outdoor workers and people with chronic medical conditions face the greatest risks.

At Deutschmann de Koning Personal Injury Law, we understand that serious injuries don't only happen in motor vehicle collisions. Negligence during extreme weather can also have devastating consequences. Whether it's an employer failing to protect workers, a landlord ignoring unsafe living conditions or an organization failing to plan for dangerous temperatures, preventable heat-related injuries can have lasting impacts.

Heat Exhaustion vs. Heat Stroke: Know the Difference

Many people use these terms interchangeably, but they're very different medical emergencies.

Heat Exhaustion

Heat exhaustion occurs when the body loses too much water and salt through sweating.

Common symptoms include:

• Heavy sweating
• Muscle cramps
• Weakness
• Headache
• Dizziness
• Nausea
• Fatigue
• Cool, clammy skin

Without treatment, heat exhaustion can quickly progress to heat stroke.

Heat Stroke

Heat stroke is a medical emergency.

It occurs when the body's cooling system fails, causing body temperature to rise rapidly.

Symptoms may include:

• Confusion
• Difficulty speaking
• Loss of consciousness
• Hot, dry skin
• Seizures
• Rapid heartbeat
• Body temperature above 40°C

Call 911 immediately if you suspect someone is experiencing heat stroke.

Delaying treatment can result in permanent brain damage, organ failure or death.

Who Is Most at Risk?

While anyone can suffer a heat-related illness, certain groups are particularly vulnerable.

These include:

• Older adults
• Infants and young children
• Outdoor workers
• Construction crews
• Farmers
• Landscapers
• Roofers
• People with heart disease or respiratory illnesses
• Individuals taking medications that affect hydration
• Athletes exercising outdoors

Checking on elderly neighbours, friends and family members during periods of extreme heat can save lives.

Outdoor Workers Need Protection

Thousands of Ontarians work outdoors throughout the summer.

Construction workers, road crews, utility workers, delivery drivers, agricultural workers and landscapers often spend hours exposed to direct sunlight.

Employers have responsibilities under Ontario's occupational health and safety laws to take reasonable steps to protect workers from foreseeable hazards, including extreme heat.

That may include:

• Providing access to drinking water.
• Allowing regular rest breaks.
• Adjusting work schedules during peak temperatures.
• Providing shaded rest areas.
• Training workers to recognize signs of heat illness.
• Developing emergency response procedures.

Ignoring these risks can lead to serious injuries that may have been entirely preventable.

Children and Hot Vehicles

Every summer, heartbreaking stories emerge about children left inside parked vehicles.

Even on a day that doesn't feel exceptionally hot, temperatures inside a vehicle can rise dramatically within minutes.

Cracking the windows offers little protection.

Children's bodies heat up much faster than adults, making them especially vulnerable to heat stroke.

Parents and caregivers should:

• Never leave a child unattended in a vehicle.
• Check the back seat before locking the doors.
• Keep vehicles locked when parked.
• Store keys out of children's reach.
• Ask a daycare or caregiver to call if a child doesn't arrive as expected.

These simple habits can prevent unimaginable tragedies.

Protecting Seniors During Heat Waves

Older adults often don't feel thirsty as quickly as younger people.

Some medications can also interfere with the body's ability to regulate temperature.

Family members should encourage seniors to:

• Drink water regularly.
• Stay in air-conditioned spaces whenever possible.
• Wear lightweight clothing.
• Limit outdoor activities during the hottest part of the day.
• Monitor for dizziness or confusion.

Community support during heat events can make a significant difference.

Recreational Activities Can Become Dangerous

Ontario summers encourage people to enjoy:

• Hiking
• Cycling
• Boating
• Gardening
• Sporting events
• Festivals
• Outdoor concerts

While these activities are healthy and enjoyable, they should be planned carefully during periods of extreme heat.

Remember to:

• Drink water before you feel thirsty.
• Wear sunscreen.
• Take frequent breaks.
• Seek shade whenever possible.
• Avoid strenuous activity during the afternoon.
• Watch for symptoms of overheating in children.

When Can Heat-Related Injuries Become a Legal Matter?

Not every heat-related illness results from negligence.

However, there are situations where another person or organization may be legally responsible.

Examples include:

• Employers failing to provide safe working conditions.
• Long-term care facilities neglecting vulnerable residents.
• Daycares failing to adequately supervise children outdoors.
• Event organizers ignoring dangerous weather conditions.
• Property owners creating hazardous conditions that contribute to heat-related injuries.

Each case depends on its unique facts.

If negligence contributed to a serious injury, legal remedies may be available.

What Should You Do After a Serious Heat-Related Injury?

If you or a loved one suffers a significant heat-related illness:

1. Seek immediate medical treatment.
2. Follow all medical recommendations.
3. Keep records of medical expenses.
4. Document where and how the incident occurred.
5. Obtain witness information if appropriate.
6. Preserve photographs or videos of the conditions.
7. Speak with an experienced Ontario personal injury lawyer if you believe negligence played a role.

Early legal advice can help preserve important evidence and clarify your rights.

Stay Safe This Summer

Extreme heat isn't simply uncomfortable—it can be deadly.

Fortunately, most heat-related illnesses are preventable through preparation, awareness and common sense.

• Drink plenty of water.
• Know the warning signs.
• Check on vulnerable family members.
• Take breaks when working outdoors.
• Never leave children or pets in parked vehicles.

By taking these simple precautions, you can enjoy everything Ontario's summer has to offer while protecting yourself and those around you.

If you or someone you love has suffered a serious injury because another person or organization failed to take reasonable precautions during extreme heat, the experienced team at Deutschmann de Koning Personal Injury Law is here to help.

We have spent decades helping injured Ontarians understand their legal rights and obtain the compensation they need to move forward with confidence.

Frequently Asked Questions

What is the difference between heat exhaustion and heat stroke?

Heat exhaustion is an early stage of heat illness that can often be treated with rest, hydration and cooling. Heat stroke is a medical emergency requiring immediate treatment and can cause permanent injury or death.

Who is most vulnerable during extreme heat?

Older adults, infants, outdoor workers, people with chronic illnesses and individuals taking certain medications face the highest risk.

Can an employer be responsible for a heat-related injury?

Potentially. Employers have legal obligations to provide a safe workplace and protect workers from foreseeable hazards, including excessive heat.

When should I contact a personal injury lawyer?

If you believe negligence contributed to a serious heat-related injury, obtaining legal advice early can help protect your rights and preserve evidence.

About Deutschmann de Koning Law

Deutschmann de Koning Law serves South-Western Ontario with offices in Kitchener-Waterloo, Cambridge, Woodstock, Brantford, Stratford and Ayr. The law practice of Robert Deutschmann and Nick de Koning focuses almost exclusively in personal injury and disability insurance matters. For more information, please visit www.ddinjurylaw.com or call us at 1-519-742-7774.