Heat Alerts

Halton Region Health Department issues heat alerts and extreme heat alerts based on a scientific evaluation. Heat alerts are issued by Halton Region's Medical Officer of Health when the combination of high heat, high humidity and other weather conditions can be hazardous to your health.

Environment Canada issues humidex advisories when forecast temperatures are expected to:

  • reach at least 31°Celsius (88°F) with overnight temperatures above 20°Celsius (68°F) for 2 or more days, and/or
  • when a humidex of 40°Celsius is expected for an extended period (2 or more days)

During a sustained heat alert, the Town of Milton activates a number of procedures to help you cope with the heat. Read on to learn about how you can stay cool and what to do if you or someone you know experiences a heat-related illness.

Cooling Centres

All residents are invited to visit any of the cooling centres listed below during a sustained heat alert to rest and cool down.

  • Milton Leisure Centre, 1100 Main St. E.
  • Milton Sports Centre, 605 Santa Maria Blvd.
  • Milton Seniors Activity Centre, 500 Childs Dr.

For a list of drop-in swimming opportunities and neighbourhood spray pad locations, visit the Town of Milton's swimming page.

What is a heat wave?

A heat wave is an extended period of excessively hot and unusually humid weather; it can last as long as weeks. It is extremely important that we take precautionary measures when this type of weather occurs.

Heat waves can also lead to other types of threats and risk, including power outages (due to the increased use of air conditioners), thunderstorms, and wildfires.

Here's what you should and shouldn't do when a heat alert is issued:


  • Stay indoors as much as possible and limit your exposure to the sun; see above for a list of Cooling Centres in Milton you can visit to stay comfortable.
  • Drink fluids often, particularly water or juice, even if you do not feel thirsty, to help your body's thermostat stay cool. (Note: People who have problems with fluid retention should consult a doctor before increasing their fluid intake.)
  • Wear lightweight, light-coloured clothing to reflect the sun's energy if you must go outside.
  • Apply a minimum of 30 SPF sunscreen and wear a wide-brimmed hat.
  • Keep pets indoors and refill their water bowls frequently.
  • Eat well-balanced, light and regular meals.
  • Check on your family, friends and neighbours, especially if they live alone.
  • Avoid extreme temperature changes; a cool shower after being outside could cause hypothermia.


  • Do strenuous activity such as running, biking and lawn care work.
  • Drink high caffeine or alcoholic drinks; they can dry out your system.
  • Eat high-protein foods; they increase your body's water loss and heat production.
  • Leave children or pets alone in a closed vehicle.

Heat-related Illness

  • Redness
  • Pain
  • Swelling of skin
  • Blisters
  • Fever
  • Headaches
  • Leave water blisters intact to speed healing and avoid infection.
  • If breaking of blister occurs, apply dry sterile dressing.
  • Serious cases should be seen by a physician.
Heat cramps
  • Painful muscle spasms - usually in the legs but possible in the abdomen
  • Apply firm pressure on cramping muscles or gently massage to relieve spasm.
  • Drink sips of water.
  • If nausea occurs, discontinue sips of water.
  • Move to a cooler place to rest in a comfortable position.
  • Be careful to note changes in your condition.
Heat exhaustion
  • Heavy sweating
  • Weakness
  • Cold, pale and clammy skin
  • Weak pulse
  • Fainting
  • Vomiting
  • Core temperature usually 38.8 degrees Celsius or higher, but normal temperature is possible
  • Move out of the sun to a cooler environment.
  • Lay down and loosen clothing.
  • Apply cool wet cloths.
  • Drink sips of water.
  • If nausea occurs, discontinue sips of water.
  • If vomiting continues, seek immediate medical attention.

Heat stroke
(Severe medical emergency)

  • High body temperature (41 degrees Celsius or higher)
  • Hot, dry skin
  • Rapid and strong pulse
  • Possible unconsciousness
  • Call 911.
  • If you are unable to get to medical help immediately, do the following:
    • Move to a cooler environment.
    • Remove outer clothing.
    • Bathe/sponge with lukewarm (not cold) water to reduce body temperature.
    • Do not drink fluids.

More Information