heat

Extreme Heat

Extreme heat events can put the public at risk of heat-related illnesses. Learn more about the risks associated with exposure to extreme heat, those who are most at risk of heat-related illnesses, and how to prepare for this type of emergency.

Heat Affects Everybody
Know the risks and how to protect yourself and your family against heat-related illnesses. Similar to a fever, extreme heat stresses your body's ability to maintain its normal temperature and can lead to a heat stroke.

During the hot summer months, be sure to watch for symptoms of heat illness, which include:
  • Dizziness of 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 periods of extreme heat, immediately to move to a cold place and drink liquids, preferably water. 

Heat stroke is considered the most serious heat-related illness and can result in death if not addressed quickly. To learn more about the symptoms of heat stroke, view the information in the section below.

If you suspect you or someone else is experiencing a heat stroke, call 911 immediately.
Heat-Related Illnesses and Symptoms
Below is a list of heat-related illnesses (in descending order of severity) and their symptoms.

HEAT STROKE

Signs of heat stroke include:
  • Headache
  • Dizziness
  • Confusion
  • Fainting
  • High body temperature (more than 40°C/104°F)
There are two types of heat stroke:
  • Classic - accompanied by little or no sweating, usually occurring in children, those who are chronically ill, and older adults
  • Exertional - accompanied by an increase in core body temperature due to strenuous exercise or occupational exposure in combination with environmental heat. Sweating is usually present.
Heat stroke is considered a medical emergency. Seek emergency help and cool the person down right away.


HEAT EXHAUSTION

Heat exhaustion is caused by excessive loss of water and salt. Symptoms include:
  • Heavy sweating
  • Weakness
  • Dizziness
  • Nausea
  • Vomiting
  • Fainting

HEAT CRAMPS

Painful muscle cramps caused by a salt imbalance resulting from a failure to replace salt lost through excessive sweating.


HEAT RASH

Red or pink rash usually found on the neck, chest and/or elbow creases, which may give a prickling sensation.


HEAT EDEMA

Heat-induced swelling frequently noticeable in the ankles, feel, and hands. Heat edema is most often seen in people who are not regularly exposed to heat.
Who is Most at Risk?
During an extreme heat event, everyone is at risk, but certain groups are more vulnerable than others, including:
  • Infants and young children
  • People who are pregnant
  • Older adults
  • People who live alone
  • People with chronic medical conditions (such as heart disease, respiratory conditions, overweight and diabetes) or mental illnesses (such as schizophrenia, depression, and dementia)
  • People experiencing homelessness, those who are underhoused, or encounter other challenges in accessing cool spaces
  • People with limited mobility
  • People who exercise vigorously outdoors, including those who play sports, cycle, or garden)
  • Outdoor workers (depending on the length of work and exertion level)
  • People who work in places where heat is emitted through industrial processes (such as barkers and dry cleaners)
Heat Warnings
Southwestern Public Health (SWPH) issues heat warnings to help you prepare for dangerous temperatures. 

There are two types of warnings:

Heat Warning: Daytime temperatures reach 31°C or higher, and nighttime temperatures are 20°C or higher for at least two days, or when it feels like 40°C or hotter for two days.

Extended Heat Warning: The same conditions as listed above, but lasting three or more days.
Where Can I Go to Cool Down?
In the event of an extreme heat warning, the City of St. Thomas may open a temporary cooling space at the Joe Thornton Community Centre:

Joe Thornton Community Centre
  • Address: 75 Caso Crossing, St. Thomas ON
  • Phone: 519-633-7112

Specific information relating to the cooling centre, including hours of operation, will be available upon opening the centre.


Additional cooling spaces in St. Thomas:

The INN
  • Overnight Shelter
  • Address: 10 Princess Ave, St. Thomas ON
  • Open 24 hours, seven days per week
  • Phone: 519-637-9898

Ignite Youth Centre
  • Address: 745 Talbot St, St. Thomas ON
  • Phone: 519-631-8820

For more information on additional cooling spaces in the surrounding area, visit the Southwestern Public Health website.
How Can I Stay Safe in the Heat?
The best way to stay safe during an extreme heat event is to be aware and stay prepared. If you have symptoms during extreme heat, as listed in the section above, you should:

  • Immediately move to a cool place (i.e. indoors)
  • Rest by sitting or lying down
  • Drink water 

PROTECT YOURSELF:
  • Drink water often (avoid caffeine and alcohol)
  • Limit outdoor activities during the hottest times of the day (11 AM - 4 PM)
  • Wear sunscreen (SPF 30 or higher), a hat, and light, loose clothing. Be sure to reapply sunscreen every 2-3 hours
  • If outside, use an umbrella, visit a shady park, or head to a cooling centre
  • If at home, take a cool shower or bath. TIP: A fan with ice water nearby creates a refreshing breeze
Keep Your Children Safe
Extreme heat and heat-related illnesses are especially dangerous for infants and young children. 

Children most at risk include those with breathing difficulties (asthma), heart conditions, kidney problems, mental and physical disabilities, developmental disorders, diarrhea, and those who take certain medications. Consult with your doctor to learn if your children's medication increases their risk of heat-related illnesses.

The following tips can help you prepare for extreme heat and keep your children safe:

  • Keep your child hydrated 
  • Keep your home cool by using an air conditioner, closing blinds or curtains during the day, avoiding using the oven, and opening your windows at night if it is safe to do so
  • Avoid exposing your child to extreme heat by rescheduling outdoor activities, or planning those activities for cooler parts of the day

TIPS TO AVOID SUN EXPOSURE:
  • Dress your child in loose-fitting, light-coloured clothing
  • Keep your child in the shade or protected from the sun with a hat/umbrella
  • Limit time spent in the sun
  • Use broad spectrum sunscreen that is SPF30 or higher
Never leave children or pets alone in a parked car. Even on cooler days when the outside temperature is moderate, the temperature inside a vehicle can be dangerously hot.