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Middlesex-London Health Unit

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Hot and Sticky Start to Fall Prompts Heat Alert for London and Middlesex County

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Even though the fall season officially starts today, some very summer-like and unseasonably hot weather is in store for the Middlesex-London area this weekend. Because Environment Canada’s forecast is calling for daytime high temperatures of 31º Celsius for Saturday, Sunday and Monday, the Middlesex-London Health Unit is issuing a Heat Alert for the next three days. The heat will be combined with very muggy conditions, with humidex values expected to reach the high 39.

Heat Alerts are issued when one or more of the following criteria are met:

• Environment Canada issues a forecast calling for a day-time high of 31º Celsius or higher for one day, or;

• Environment Canada issues a forecast calling for a Humidex value of 40 or higher for one day.

When high temperatures and humidity settle on the Middlesex-London region for an extended length of time, they can result in increased health risks. Anyone who finds they are suffering symptoms associated with extreme temperature conditions should seek medical attention immediately either by calling 911 or going to the nearest Emergency Department.

To avoid heat-related illness, follow these tips:

• Drink plenty of water and natural juices throughout the day, even if you don't feel very thirsty. Remember to take sips often and not to guzzle your drink.
• Avoid drinking alcoholic beverages, coffee and cola.
• When possible, avoid spending too much time outdoors. If you must be outside, seek shade as much as possible. Plan outdoor activities in the early morning or evening.
• Wear a wide-brimmed hat when outdoors.
• Keep window shades or drapes drawn and blinds closed on the sunny side of your home.
• Avoid turning on electric lights in the home.
• Take a cool bath or shower periodically or cool down with cool, wet towels.
• Wear loose fitting, light clothing.
• Avoid eating heavy meals and using your oven.
• Avoid intense or moderately intense physical activity.
• Never leave a child or pet in a parked car or sleeping outside in direct sunlight.
• Use fans to draw cool air at night, but do not rely on a fan as a primary cooling device during extended periods of excessive heat.
• Consult your doctor or pharmacist about the side effects of any medications you are taking.
• Reduce the use of personal vehicles, stop unnecessary idling; avoid using oil-based paints and glues, pesticides and gas-powered small engines.

If you experience any of the following symptoms of heat illness, seek help from a friend, relative or a doctor:

• Rapid breathing
• Weakness or fainting
• More tiredness than usual
• Headache
• Confusion

You can help someone with heat illness by doing the following:

Calling for help. Call 911, consult a healthcare provider or call Telehealth Ontario (1-866-797-0000 or TTY at 1-877-797-0007);
• Moving the person to a cooler location.
• Removing excess clothing from the person.
• Cooling the person with lukewarm water, by sponging or bathing.
• Giving the person sips of cool water if they are not nauseated or vomiting. Do not give ice cold water.

As an owner or operator of residential buildings, landlords can take these actions to decrease the risk of heat-related illness to residents:

• Provide residents access to a cooler spot for several hours at a time (e.g. a common room with air conditioning or a basement area).
• Keep windows in hallways slightly open to allow air to circulate.
• Use fans to draw cool air at night, but do not rely on a fan as a primary cooling device during extended periods of excessive heat.
• Provide heat safety information to residents or post the information in common areas (e.g. by the elevator, in the lobby, etc.).
• Have building staff check on at-risk residents every few hours.
• Advise residents to drink lots of water and natural fruit juices, even if they don't feel thirsty.
• Ask residents to keep windows open and the drapes drawn.
• Keep lights off. Do not use stove or oven.
• Suggest residents cool down with cool baths, showers, foot baths or by placing cool, wet towels on their necks or underarms.
• Suggest tenants avoid midday sun or heat and go outside in the morning or evening when it is cooler.

For more information about extreme weather warnings, heat-related illness, and/or humidity visit:

For information about pet care please contact the London Animal Care Centre 519-685-1330 or visit

Media Contact:

Dan Flaherty, Communications Manager, Middlesex-London Health Unit, 519-663-5317 ext. 2448, or 519-617-0564 (cell.)


Randy Walker, Public Health Inspector, Middlesex-London Health Unit

Tags: fall 2017 heat alert, unseasonably hot weather