Evaluating cumulative temperature indicators for heat alert and response systems : a case study in Vancouver, British Columbia
department or school: Medicine, Faculty of
department or school: Population and Public Health (SPPH), School of
data provider: DSpace
degree campus: UBCV
creator: Hu, Alexi Tianyang
issued: 2025-10-20T19:36:44Z
issued: 2025
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: Extreme heat events (EHEs) are escalating in frequency, intensity, and duration due to climate change, posing significant health risks. To mitigate their impacts, many countries, including Canada, have established heat-health warning systems (HHWSs). However, these systems often rely on absolute temperature thresholds that require all conditions to be met simultaneously. This rigidity can overlook different sequences of day-night heat that accumulate over multiple days, potentially leading to missed warnings. In this study, seven cumulative temperature metrics were created by summing daily high and overnight low temperatures over one to three days. To assess each metricâs relationship with all-cause mortality, heat-related ED visits, and ambulance dispatches in Western Metro Vancouver (WMV) from 2008-2023, generalized additive models with negative binomial distributions were fitted. The statistical performance of the metrics was evaluated using significance tests, the Akaike Information Criterion (AIC), and forecasting accuracy. All cumulative metrics demonstrated stable and comparable statistical performance. Given its applicability, the High+Low+High (HLH) metricâsumming two daily highs and one overnight lowâwas selected as an example for further analyses. A split value analysis was performed by dividing HLH into one hundred equally spaced intervals and creating a binary variable for each interval, refitting a model to determine the odds ratio (OR) at each split. Points at which the OR for the three outcomes became significantly greater than 1.0 were designated as baseline thresholds. 58°C (all-cause mortality), 47°C (ED visits), and 42°C (ambulance dispatches) were identified as the baseline points. Using the mortality-based threshold as a template, further âseparate baseline thresholdsâ of 51°C and 15°C were identified for two daily highs (HH) and overnight low (L) respectively. Accordingly, an HLH threshold algorithm was formulated such that the OR of mort…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/90401
note: EVALUATING CUMULATIVE TEMPERATURE INDICATORS FOR HEAT ALERT AND RESPONSE SYSTEMS: A CASE STUDY IN VANCOUVER, BRITISH COLUMBIA by Alexi Tianyang Hu M.A., The University of Victoria, 2020 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Population and Public Health) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) February 2025 © Alexi Tianyang Hu, 2025 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the thesis entitled: Evaluating cumulative temperature indicators for heat alert and response systems: a case study in Vancouver, British Columbia submitted by Alexi Tianyang Hu in partial fulfilment of the requirements for the degree of Master of Science in Population and Public Health Examining Committee: Michael Brauer, Professor, Population and Public Health, UBC Co-Supervisor Sarah Henderson, Professor, Population and Public Health, UBC Co-supervisor Eric Lavigne, Senior Scientist, Health Canada Supervisory Committee Member Rachel White, Assistant Professor, Earth, Ocean and Atmospheric Sciences, UBC Additional Examiner iii Abstract Extreme heat events (EHEs) are escalating in frequency, intensity, and duration due to climate change, posing significant health risks. To mitigate their impacts, many countries, including Canada, have established heat-health warning systems (HHWSs). However, these systems often rely on absolute temperature thresholds that require all conditions to be met simultaneously. This rigidity can overlook different sequences of day-night heat that accumulate over multiple days, potentially leading to missed warnings. In this study, seven cumulative temperature metrics were created by summing daily high and overnight low temperatures over one to three days. To assess each metricâs relationship with all-cause mortality, heat-related ED visits, and ambulance d…
has type: Thesis/Dissertation
date issued: 2025-05
is shown at: 10.14288/1.0448095
language: eng
degree discipline: Population and Public Health
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Brauer, Michael (Of University of British Columbia)
contributor: Henderson, Sarah B.
type: Text
identifier URI: http://hdl.handle.net/2429/90401