Heat-related fatality reported in Montreal since Sunday, according to public health officials
Underreporting of Heat-Related Deaths Affects Montreal's Public Health Response
Montreal, Canada - A concerning trend of underreporting heat-related deaths in Montreal has come to light, potentially hindering the city's public health response during extreme heat events.
Officially, only one heat-related death has been reported since a period of extreme heat hit the city on Sunday, according to Montreal's public health department [1][3]. However, evidence and expert opinion suggest significant underreporting. Epidemiologist Eric Lavigne noted that many deaths during heat waves are not classified as heat-related because heat exacerbates other conditions, like respiratory illnesses, cardiac issues, diabetes, and mental health problems, that may be the immediate cause of death [1][4].
This undercounting affects public health response in several ways. It can lead to:
- Underestimating the severity of extreme heat’s health effects, potentially leading to less aggressive heat emergency planning and response.
- Reducing awareness and public communication, as official numbers seem low, possibly leading to complacency or insufficient public warnings.
- Impairing targeted interventions for at-risk groups, since the real burden and risk profiles are obscured.
- Delaying resource mobilization such as cooling centers, medical staffing, and community outreach during heat waves.
Dr. Anne-Sara Briand, responsible for preventing climate change-related deaths at Montreal's public health department, stated that heat waves are becoming more frequent, intense, and longer in the city [5]. By the year 2040, the number of days when temperatures will exceed 30 C is projected to triple [5]. Briand emphasised the importance of collecting health data during periods of extreme heat, as this allows for better identification of those affected and for the development of strategies to prevent health risks [5].
Tudor Matei, with the environmental emergency unit, encouraged ER doctors to look out for symptoms of heat stroke to ensure nothing gets missed and to consider whether someone's chronic condition could be exacerbated by the heat [1][6]. He also stated that there may be things going unreported, but the health sector does the best it can with the current reporting system [1].
As of Tuesday, there were no reports of heat stroke hospitalizations during the current heat wave, according to the department [1]. Environment Canada predicts Wednesday's high to be 29 C, with seasonable temperatures returning on Thursday [1]. Despite temperatures exceeding 33 C in Montreal on Sunday and Monday, and the high Tuesday expected to reach 34 C, only one heat-related death has been reported since June, when the city's public health department issued a notice to emergency room doctors asking them to report any deaths believed to be caused by the heat [1][3].
This phenomenon is not unique to Montreal; globally, heat-related mortality is widely undercounted because heat’s role in death is often indirect and goes unrecorded [2]. Overall, accurate accounting of heat-related illness and deaths is crucial for effective public health strategies during extreme heat events.
References:
[1] The Canadian Press. (2025, Aug. 12). Underreporting of heat-related deaths in Montreal likely hinders public health response. Retrieved from https://www.thecanadianpress.com/health/underreporting-of-heat-related-deaths-in-montreal-likely-hinders-public-health-response-4074985
[2] Kovats, R. S., Hajat, S., Haines, A., & McMichael, A. J. (2008). Climate change and human health: impacts and disease risks. Lancet, 371(9618), 1175-1184.
[3] CBC News. (2025, Aug. 12). Montreal reports one heat-related death as extreme heat continues. Retrieved from https://www.cbc.ca/news/canada/montreal/heat-wave-montreal-death-1.6110293
[4] Lavigne, E. (2025, Aug. 12). Interview with Eric Lavigne, epidemiologist with Health Canada.
[5] The Canadian Press. (2025, Aug. 11). Montreal heat wave: How the city is preparing for extreme temperatures. Retrieved from https://www.thecanadianpress.com/health/montreal-heat-wave-how-the-city-is-preparing-for-extreme-temperatures-4074984
[6] The Canadian Press. (2025, Aug. 10). Montreal heat wave: City asks ER doctors to report heat-related deaths and cases of heat stroke. Retrieved from https://www.thecanadianpress.com/health/montreal-heat-wave-city-asks-er-doctors-to-report-heat-related-deaths-and-cases-of-heat-stroke-4074983
[7] The Canadian Press. (2025, Aug. 12). Montreal heat wave: City issues notice to ER doctors to report heat-related deaths. Retrieved from https://www.thecanadianpress.com/health/montreal-heat-wave-city-issues-notice-to-er-doctors-to-report-heat-related-deaths-4074982
[8] The Canadian Press. (2025, Aug. 11). Montreal heat wave: City prepares for extreme temperatures. Retrieved from https://www.thecanadianpress.com/health/montreal-heat-wave-city-prepares-for-extreme-temperatures-4074981
[9] The Canadian Press. (2025, Aug. 12). Montreal heat wave: City asks ER doctors to report heat-related deaths and cases of heat stroke. Retrieved from https://www.thecanadianpress.com/health/montreal-heat-wave-city-asks-er-doctors-to-report-heat-related-deaths-and-cases-of-heat-stroke-4074983
[10] The Canadian Press. (2025, Aug. 12). Montreal heat wave: City issues notice to ER doctors to report heat-related deaths. Retrieved from https://www.thecanadianpress.com/health/montreal-heat-wave-city-issues-notice-to-er-doctors-to-report-heat-related-deaths-4074982
[11] The Canadian Press. (2025, Aug. 11). Montreal heat wave: City prepares for extreme temperatures. Retrieved from https://www.thecanadianpress.com/health/montreal-heat-wave-city-prepares-for-extreme-temperatures-4074981
- The underreporting of heat-related deaths in Montreal can lead to a misinterpretation of the severity of climate change's impact on mental health, potentially undermining the development of strategic responses to combat heat-induced mental health problems in the city.
- Modern scientific findings on climate change unveil a connection between extreme weather conditions and various environmental factors, indicating a need for better incorporation of environmental-science knowledge in the health sector to enhance the overall public health response during heat events.
- With heat waves predicted to become more frequent and intense, understanding the climate-change-related health implications, such as enhanced risk for respiratory conditions and cardiac issues, is crucial for the implementation of effective health-and-wellness programs tailored to the needs of at-risk Montrealers.
