Montreal's Heat Wave Action Plan

Central Canada has been suffering from the heat for days, and with temperatures now reaching the mid-30s and the humidex (humidity index) tipping over 40ºC (104ºF) the city of Montreal is taking action to prevent heat-related illness and deaths.

Defining a heat wave

The American Meteorological Society defines a heat wave as a "period of abnormally and uncomfortably hot and usually humid weather." A standard application of that definition is a period of at least three days where heat reaches or exceeds 32ºC, but because weather patterns vary from one country or region to another, standards for an official heat wave will also vary. Quebec has a definition that uses a 30ºC minimum temperature, which means Montreal's heat wave started some days ago.

Health risks associated with heat waves

Anyone can suffer from heat stroke during weather extremes such as we are currently experiencing in central Canada at the moment, but certain people have an elevated risk and should take extra precautions. The elderly, children under age 5, and people suffering from any chronic cardiac or respiratory condition including asthma are in the population at elevated risk. Also a concern are people who spend a lot of time out in the sun: those who work outdoors, the homeless, and athletes who spend time training or competing outdoors. Even adolescents can be at risk, as they tend to be active outdoors.

People who take certain medications may be at elevated risk for sun burn during a heat wave, or may be more susceptible to heat stroke. The high heat and humidity can aggravate existing conditions such as high blood pressure or asthma. It can also result in fatigue or dehydration, or in heat stroke. Smog warnings should also be taken into consideration when evaluating risk levels.

Opération canicule: Montreal's heat wave response plan

Based on data collected over twenty years, an average of 100 people could be expected to die from heat and humidity conditions such as Montreal is having right now. The city has formed an action plan to prevent heat related illness and death. Montreal's swimming and wading pools are extending their hours during the heat wave, and the city is setting up cooling centres for those who are at risk and who do not have air conditioning at home. People will be able to take refuge in the centres for up to three hours at a time. Citizens can call 311 to find a cooling centre in their area. Police and fire services will be going door to door to check on citizens, and transport to a cooling centre can be arranged for citizens with limited mobility.

What to do about heat related illness

Montrealers who feel ill during the heat wave are encouraged to contact their physician or call 811 to reach a bilingual Info-Santé nurse. Heat stroke is a severe heat-related condition, in which a person stops sweating and the body is no longer able to regulate its core temperature. According to Health Canada, symptoms of heat stroke include: a body temperature above 40ºC, dizziness or fainting, confusion, nausea, and a throbbing headache. Pulse may be rapid, and breathing may be rapid and shallow. Although some people with heat related conditions may have dry, red, hot skin, this is not always the case.

Heat stroke is a medical emergency, and if suspected emergency services should be accessed immediately by calling 911. If at all possible, remove the person to a shaded or air conditioned area while waiting for the ambulance. Cool them with by sponging them or lightly spraying with water, or cover them with damp sheets. Provide water or a caffeine-free cool drink if they are able to drink on their own.

Heat wave: Elsewhere in Canada

The heat and humidity have affected much of Ontario and Quebec, and some parts of New Brunswick have also been under humidex warnings from Environment Canada. Some parts of British Columbia are seeing an increase in temperature, after this week's cooler days. A heat wave may be in the works there too. Other Canadian cities, such as Toronto, have also set up cooling centres and are encouraging citizens with elderly family and neighbours to check in on them more frequently until the weather returns to normal.

Seniors can find a hot weather information card, with contact numbers and advice for coping with the heat, on the Montreal Public Health web site. Other communiques and information about surviving a heat wave can be had on the site, but may not necessarily be available in English.

Sources:

Daphné Cameron, "Opération canicule." La Presse

Beatrice Fantoni, "Cooling centres open for relief from heat." The Gazette

"Extreme heat events." Health Canada

"Heat stroke: First aid." Mayo Clinic

"Heat wave." AMS Glossary

"Hot weather hits Ontario, Quebec." CBC News