Related Experiment Video
Updated: Jun 23, 2026

A Preclinical Model of Exertional Heat Stroke in Mice
Published on: July 1, 2021
Sex Differences in the Effects of High Temperature on Cardiovascular Disease Hospitalizations in Montreal
Yusheng Zhou1,2, Sasha Ramkhelawan3, Bulemba Katende1
1Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, Canada.
Background:
Climate change has increased temperatures in Canada. Although heat-related mortality is well documented, less is known about its impact on cardiovascular disease (CVD) morbidity, particularly hospitalization patterns. This study examines the association between ambient temperature and CVD hospitalizations in Montreal, focusing on sex-stratified vulnerability.
Methods:
A time-series analysis was conducted in Montreal, Quebec, examining CVD hospitalizations during the warm season (May 1-September 30) from 2018-2022. Ambient temperature was represented by daily mean temperature. Analyses were stratified by sex and heat vulnerability index (HVI) levels. The HVI integrates multiple vulnerability dimensions (exposure index, sensitivity index, and coping capacity index); higher HVI scores indicate greater vulnerability to extreme heat impacts. Daily mean temperature (lag, 0-7 days) and CVD hospitalizations were analyzed using distributed lag nonlinear models, adjusting for possible confounders.
Results:
Among 262,740 CVD patient hospitalizations (mean age 76.4 years; 49.6% female), the relative risk (RR) for CVD hospitalization at the 99th percentile of temperature (28.1°C), as compared to the identified minimum morbidity temperature (MMT; 23°C) for the total population was 1.08 (95% confidence interval [CI]: 1.05-1.11). Although overall heat-related risk was similar between sexes, vulnerability components revealed differences. Female participants exhibited significant cardiovascular risk in areas with poor adaptive resources based on coping capacity index (RR = 1.13, 95% CI: 1.04-1.23), whereas male patients did not (RR = 1.03, 95% CI: 0.96-1.12), suggesting greater susceptibility when community-level resources are limited.
Conclusions:
Female participants demonstrated greater vulnerability in areas lacking adaptive resources, indicating that sex-specific heat-protection strategies should prioritize enhancement of community-level cooling infrastructure and support systems.
Related Concept Videos
Factors Affecting Body Temperature
Factors may include:
Homeostatic Imbalances in Body Temperature
Increased Body Temperature
Assessing Body Temperature - Temporal Artery
Step 1: Perform hand hygiene and don a fresh pair of gloves to prevent cross-infection and ensure patient safety.
Step 2: Explain the procedure to the patient to establish trust. Clear communication establishes trust with the patient, ensures they understand what to expect, promotes cooperation, and enhances comfort during the procedure.
Step 3: Assess the patient's forehead...
Responses to Heat and Cold Stress
Assessing Body Temperature - Axilla
Step 1: Perform hand hygiene and put on clean gloves to maintain infection control and prevent cross-contamination.
Step 2: Prepare the patient by explaining the procedure to ensure understanding and cooperation. Ensure privacy, expose the axilla, and inform the patient that minimal movement is crucial for an accurate reading.
Step 3: Adjust the patient’s clothing to expose only the axilla. It minimizes...