Southern Ontario’s first heat wave of the summer

It's hot. It's humid. And there's no relief in sight. CTV's Ashley Bacon has the details.

A heat wave has settled over southern Ontario.

Tuesday marked the start of what’s expected to be a prolonged stretch of hot and humid weather.

Environment Canada said temperatures could reach 33, and even as high as 36 degrees Celsius.

With the humidity, it could feel closer to 37 or possibly 45.

The heat event will continue until Friday or Saturday.

“The hottest days are expected to be Wednesday and Thursday, with maximum temperatures of 34 to 36 degrees Celsius expected,” Environment Canada said in Tuesday’s alert. “Minimum [overnight] temperatures of 21 to 24 degrees Celsius will provide little relief from the heat.”

The agency also warned that the hot and humid weather could impact air quality.

As of noon Tuesday, southwestern Ontario was listed as moderate risk on Air Quality Health Index. But Environment Canada warned it could creep into the high-risk category as the heat wave continues.

Signs of heat illness

Heat illness is a serious concern when the mercury rises, especially in older adults, infants, young children, pregnant people, those with physical or mental illnesses, mobility issues, people who work outside and the homeless community.

Symptoms of heat exhaustion include:

• Headache
• Nausea or vomiting
• Dizziness or fainting
• Extreme thirst
• Dark urine and decreased urination
• Intense fatigue
• Confusion or lack of coordination
• Skin rash
• Muscle cramps
• Heavy sweating
• Rapid breathing and heartbeat

Heat stroke, by comparison, is considered a medical emergency.

Symptoms include:

• High body temperature
• Very hot, red skin
• Confusion or change in consciousness
• Dizziness or fainting
• No sweating

If someone is experiencing heat stroke, experts advise moving them to a cool place, giving them water and placing ice packs on their body. Call 911 immediately.

Beating the heat

The key to avoiding heat illness is to plan ahead.

Here are a few things to keep in mind:

• Know the weather forecast before going outside
• Modify your plans according to the weather
• Drink plenty of cool liquids, especially water, even before you feel thirsty
• Avoid drinks that are high in sugar, caffeine or alcohol
• Wear loose-fitting, light-coloured clothing made of breathable fabric
• Seek shade
• Avoid sun exposure if you can
• Take breaks as needed
• Avoid using your oven
• Take a cool shower or bath
• Take a break by spending a few hours in a cool place
• Close blinds and shades,
• Turn on air conditioning or use a fan

Cooling centres

The best way to get relief from the heat and humidity is to seek out a designated cooling centre.

The Region of Waterloo has locations listed on their website. They include libraries, community centres, museums and regional offices.

The map also includes a list of public swimming pools and splash pads.

Protecting your pets

Never leave pets inside a hot vehicle.

Dogs can also experience heatstroke, and it could lead to organ failure or even death.

Signs of an overheated pet include:

• Excessive panting
• Drooling
• Vomiting
• Collapsing
• Lethargy
• Tongue can appear red or hang out of their mouth

If your pet is suffering from the heat, it’s a good idea to gradually cool them down. Experts suggest using a cool blanket or towel that is wet. Avoid using ice.

Owners should keep pets at home when the temperature climbs but if they need to go outside, keep them off the pavement as much as possible, only go for a short walk, or take them out in the morning or evening when it’s cooler.

Anyone concerned about the well-being of an animal is advised to call 911.