title: Heat-related deaths in hot cities: estimates of human tolerance to high temperature thresholds.
abstract: In this study we characterized the relationship between temperature and mortality in central Arizona desert cities that have an extremely hot climate. Relationships between daily maximum apparent temperature (ATmax) and mortality for eight condition-specific causes and all-cause deaths were modeled for all residents and separately for males and females ages <65 and ≥ 65 during the months May-October for years 2000-2008. The most robust relationship was between ATmax on day of death and mortality from direct exposure to high environmental heat. For this condition-specific cause of death, the heat thresholds in all gender and age groups (ATmax = 90-97 °F; 32.2-36.1 °C) were below local median seasonal temperatures in the study period (ATmax = 99.5 °F; 37.5 °C). Heat threshold was defined as ATmax at which the mortality ratio begins an exponential upward trend. Thresholds were identified in younger and older females for cardiac disease/stroke mortality (ATmax = 106 and 108 °F; 41.1 and 42.2 °C) with a one-day lag. Thresholds were also identified for mortality from respiratory diseases in older people (ATmax = 109 °F; 42.8 °C) and for all-cause mortality in females (ATmax = 107 °F; 41.7 °C) and males <65 years (ATmax = 102 °F; 38.9 °C). Heat-related mortality in a region that has already made some adaptations to predictable periods of extremely high temperatures suggests that more extensive and targeted heat-adaptation plans for climate change are needed in cities worldwide.
authors.affiliation: School of Human Evolution & Social Change, Arizona State University, Tempe, AZ 85287, USA. sharon.harlan@asu.edu.
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Harlan
authors.affiliation: School of Human Evolution & Social Change, Arizona State University, Tempe, AZ 85287, USA. gchowell@asu.edu.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Chowell
authors.affiliation: School of Mathematical & Statistical Sciences, Arizona State University, Tempe, AZ 85287, USA. syang65@asu.edu.
authors.forename: Shuo
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Biomedical Informatics, Arizona State University, 13212 East Shea Boulevard, Scottsdale, AZ 85259, USA. Diana.Petitti@asu.edu.
authors.forename: Diana B
authors.initials: DB
authors.lastname: Petitti
authors.affiliation: School of Human Evolution & Social Change, Arizona State University, Tempe, AZ 85287, USA. Emmanuel.J.Morales@asu.edu.
authors.forename: Emmanuel J
authors.initials: EJ
authors.lastname: Morales Butler
authors.affiliation: Department of Engineering and Computing Systems, Polytechnic School, Arizona State University, 330M Peralta Hall, Mesa, AZ 85212, USA. bruddell@asu.edu.
authors.forename: Benjamin L
authors.initials: BL
authors.lastname: Ruddell
authors.affiliation: Spatial Sciences Institute, University of Southern California, 3616 Trousdale Parkway, AHF B55, Los Angeles, CA 90089, USA. druddell@usc.edu.
authors.forename: Darren M
authors.initials: DM
authors.lastname: Ruddell
mesh_terms: D000368:Aged; D001130:Arizona; D002423:Cause of Death; D002947:Cities / Q000706:statistics & numerical data*; D005260:Female; D018882:Heat Stress Disorders / Q000401:mortality*; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality