{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T13:14:02Z","timestamp":1789478042926,"version":"build-2803163510"},"reference-count":59,"publisher":"Wiley","issue":"11","license":[{"start":{"date-parts":[[2025,9,3]],"date-time":"2025-09-03T00:00:00Z","timestamp":1756857600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"},{"start":{"date-parts":[[2025,9,3]],"date-time":"2025-09-03T00:00:00Z","timestamp":1756857600000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["American J Industrial Med"],"published-print":{"date-parts":[[2025,11]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Rationale<\/jats:title>\n                    <jats:p>Industry guidelines recommend work\u2010rest schedules to prevent unsafe core temperature elevations (&gt; 38.0\u00b0C or &gt; \u03941.0\u00b0C above baseline resting) in an \u201caverage\u201d worker exposed to occupational heat stress. While permissible initial work durations (initial stay times [IST]) before implementing rest schedules have been suggested, existing data are limited to moderate\u2010intensity efforts.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>The objective of this study was to assess whether factors of sex and age influence IST during heavy\u2010intensity work.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We assessed work durations before reaching unsafe core temperature thresholds (i.e., &gt; 38.0\u00b0C or &gt; \u03941.0\u00b0C above baseline resting) among young (18\u201330 years) and older (50\u201369 years) males and females during simulated heavy\u2010intensity work at 26\u00b0C, 29\u00b0C, and 32\u00b0C wet\u2010bulb globe temperatures (WBGT).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Findings<\/jats:title>\n                    <jats:p>\n                      The likelihood of surpassing a core temperature of 38.0\u00b0C significantly increased at 32\u00b0C WBGT (hazard ratio [95% confidence interval]: 2.0 [1.5, 2.7],\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.001), but not at 29\u00b0C WBGT (1.1 [0.9, 1.4],\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.342), compared to 26\u00b0C WBGT. Median (interquartile range) durations to reach 38.0\u00b0C across groups were 32 (23\u201352), 29 (23\u201347), and 26 (18\u201335) minutes at 26\u00b0C, 29\u00b0C, and 32\u00b0C WBGT, respectively. The likelihood of reaching \u03941.0\u00b0C above baseline resting significantly increased at both 32\u00b0C (3.8 [2.6, 5.4],\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.001) and 29\u00b0C WBGT (1.5 [1.1, 2.0],\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.001), with median durations being 55 (40\u201382), 42 (35\u201356), and 33 (29\u201342) min, respectively. Older females were more likely to reach 38.0\u00b0C (2.4 [1.3, 4.3],\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.004) and \u03941.0\u00b0C above baseline resting (2.5 [1.4, 4.7],\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.003) compared to young males. No other sex\u2010 or age\u2010related differences were detected (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&gt;\u20090.145).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Impact<\/jats:title>\n                    <jats:p>These findings highlight the heightened vulnerability of older females during heavy\u2010intensity occupational heat stress, emphasizing the need for tailored guidelines to ensure equitable workforce protection.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1002\/ajim.70015","type":"journal-article","created":{"date-parts":[[2025,9,4]],"date-time":"2025-09-04T02:39:57Z","timestamp":1756953597000},"page":"949-964","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Defining Sex\u2010 and Age\u2010Specific Initial Stay Times for Continuous Heavy\u2010Intensity Work in Hot Environments Before Heat\u2010Mitigation Controls Are Implemented\u2014Part B"],"prefix":"10.1002","volume":"68","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9509-7682","authenticated-orcid":false,"given":"Fergus K.","family":"O'Connor","sequence":"first","affiliation":[{"name":"Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa Ottawa Ontario Canada"},{"name":"School of Health Sciences and Social Work, Griffith University Southport Queensland Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8772-7506","authenticated-orcid":false,"given":"Kristina\u2010Marie T.","family":"Janetos","sequence":"additional","affiliation":[{"name":"Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa Ottawa Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4081-794X","authenticated-orcid":false,"given":"Brodie J.","family":"Richards","sequence":"additional","affiliation":[{"name":"Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa Ottawa Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-3445-2496","authenticated-orcid":false,"given":"Roberto C.","family":"Harris\u2010Mostert","sequence":"additional","affiliation":[{"name":"Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa Ottawa Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-2893-8626","authenticated-orcid":false,"given":"Katie E.","family":"Wagar","sequence":"additional","affiliation":[{"name":"Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa Ottawa Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5460-8167","authenticated-orcid":false,"given":"Leonidas G.","family":"Ioannou","sequence":"additional","affiliation":[{"name":"Department of Automatics Biocybernetics and Robotics, Jo\u017eef Stefan Institute Ljubljana Slovenia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2729-2077","authenticated-orcid":false,"given":"James J.","family":"McCormick","sequence":"additional","affiliation":[{"name":"Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa Ottawa Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5922-4082","authenticated-orcid":false,"given":"Robert D.","family":"Meade","sequence":"additional","affiliation":[{"name":"Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa Ottawa Ontario Canada"},{"name":"Department of Epidemiology T.H. Chan School of Public Health, Harvard University Boston Massachusetts USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4192-474X","authenticated-orcid":false,"given":"Emily J.","family":"Tetzlaff","sequence":"additional","affiliation":[{"name":"Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa Ottawa Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8324-717X","authenticated-orcid":false,"given":"Ronald J.","family":"Sigal","sequence":"additional","affiliation":[{"name":"Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa Ottawa Ontario Canada"},{"name":"Department of Medicine Cumming School of Medicine, University of Calgary Calgary Alberta Canada"},{"name":"Department of Cardiac Sciences Cumming School of Medicine, University of Calgary Calgary Alberta Canada"},{"name":"Department of Community Health Sciences Cumming School of Medicine, University of Calgary Calgary Alberta Canada"},{"name":"Clinical Epidemiology Program, Ottawa Hospital Research Institute Ottawa Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6075-3176","authenticated-orcid":false,"given":"W. Shane","family":"Journeay","sequence":"additional","affiliation":[{"name":"Departments of Medicine and Community Health and Epidemiology Dalhousie Medicine New Brunswick and Dalhousie University Saint John New Brunswick Canada"},{"name":"Department of Medicine Division of Physical Medicine and Rehabilitation, University of Toronto Toronto Ontario Canada"},{"name":"Department of Rehabilitative Care Providence Healthcare\u2010Unity Health Toronto Toronto Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8683-6973","authenticated-orcid":false,"given":"Glen P.","family":"Kenny","sequence":"additional","affiliation":[{"name":"Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa Ottawa Ontario Canada"},{"name":"Clinical Epidemiology Program, Ottawa Hospital Research Institute Ottawa Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2025,9,3]]},"reference":[{"key":"e_1_2_11_2_1","doi-asserted-by":"publisher","DOI":"10.1177\/10482911241298948"},{"key":"e_1_2_11_3_1","volume-title":"Threshold Limit Values for Chemical Substances and Physical Agents & Biological Exposure Indices","author":"American Conference of Governmental Industrial Hygienists","year":"2024"},{"key":"e_1_2_11_4_1","doi-asserted-by":"publisher","DOI":"10.1080\/15459624.2017.1321844"},{"key":"e_1_2_11_5_1","doi-asserted-by":"publisher","DOI":"10.1139\/apnm-2022-0003"},{"key":"e_1_2_11_6_1","doi-asserted-by":"publisher","DOI":"10.1249\/MSS.0000000000002698"},{"key":"e_1_2_11_7_1","doi-asserted-by":"publisher","DOI":"10.1139\/apnm-2021-0550"},{"key":"e_1_2_11_8_1","unstructured":"F. K.O'Connor K.\u2010M. T.Janetos B. J.Richards et al. \u201cDefining Work Duration Prior to the Implementation of Work\u2010rest Allocations in Young and Older Males and Females During Simulated Moderate Intensity Work in Hot Environments \u2010 Part A \u201dAmerican Journal of Industrial Medicine(2025) forthcoming."},{"key":"e_1_2_11_9_1","unstructured":"Government of Canada(2022) https:\/\/climate.weather.gc.ca\/climate_data\/daily_data_e.html?StationID=51459."},{"key":"e_1_2_11_10_1","doi-asserted-by":"publisher","DOI":"10.1097\/EE9.0000000000000189"},{"key":"e_1_2_11_11_1","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00722.2014"},{"key":"e_1_2_11_12_1","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00637.2012"},{"key":"e_1_2_11_13_1","doi-asserted-by":"publisher","DOI":"10.1249\/MSS.0000000000002373"},{"key":"e_1_2_11_14_1","doi-asserted-by":"publisher","DOI":"10.1007\/s12147-020-09257-0"},{"key":"e_1_2_11_15_1","doi-asserted-by":"publisher","DOI":"10.1080\/15459624.2015.1077966"},{"key":"e_1_2_11_16_1","doi-asserted-by":"publisher","DOI":"10.1080\/15459624.2012.693880"},{"key":"e_1_2_11_17_1","doi-asserted-by":"publisher","DOI":"10.1080\/23328940.2024.2361223"},{"key":"e_1_2_11_18_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ssci.2019.03.009"},{"key":"e_1_2_11_19_1","doi-asserted-by":"publisher","DOI":"10.1093\/workar\/waab014"},{"key":"e_1_2_11_20_1","doi-asserted-by":"publisher","DOI":"10.1080\/15459624.2015.1043054"},{"issue":"5","key":"e_1_2_11_21_1","first-page":"303","article-title":"A Formula to Estimate the Approximate Surface Area If Height and Weight Be Known. 1916","volume":"5","author":"Du Bois D.","year":"1989","journal-title":"Nutrition"},{"key":"e_1_2_11_22_1","volume-title":"Certified Fitness Appraiser Resource Manual. Determination of Aerobic Power","author":"Canadian Society of Exercise Physiology","year":"1986"},{"key":"e_1_2_11_23_1","volume-title":"Ergonomics\u2013Evaluation of Thermal Strain by Physiological Measurements","author":"International Standards Organization","year":"2004"},{"key":"e_1_2_11_24_1","unstructured":"M.Terry Therneau. A Package for Survival Analysis in R. R package version 3.8\u20103 ed. (2024)."},{"key":"e_1_2_11_25_1","unstructured":"R. Core Team R: A Language and Environment for Statistical Computing(R Foundation for Statistical Computing 2019) https:\/\/www.R-project.org\/."},{"key":"e_1_2_11_26_1","unstructured":"GAMLj: General Analyses for Linear Models in Jamovi [Jamovi Module] (2025) https:\/\/jamovi.org."},{"key":"e_1_2_11_27_1","doi-asserted-by":"publisher","DOI":"10.1287\/mnsc.6.3.324"},{"key":"e_1_2_11_28_1","doi-asserted-by":"publisher","DOI":"10.3390\/ijerph21030371"},{"key":"e_1_2_11_29_1","doi-asserted-by":"publisher","DOI":"10.1080\/23328940.2022.2094160"},{"key":"e_1_2_11_30_1","doi-asserted-by":"publisher","DOI":"10.3390\/ijerph20054580"},{"key":"e_1_2_11_31_1","doi-asserted-by":"publisher","DOI":"10.1249\/MSS.0000000000000886"},{"key":"e_1_2_11_32_1","doi-asserted-by":"publisher","DOI":"10.1080\/15459624.2019.1612523"},{"key":"e_1_2_11_33_1","doi-asserted-by":"publisher","DOI":"10.1080\/23328940.2017.1338210"},{"key":"e_1_2_11_34_1","doi-asserted-by":"publisher","DOI":"10.3390\/app13158561"},{"key":"e_1_2_11_35_1","doi-asserted-by":"publisher","DOI":"10.1002\/j.2040-4603.2013.tb00536.x"},{"key":"e_1_2_11_36_1","doi-asserted-by":"publisher","DOI":"10.1152\/jappl.1963.18.1.51"},{"key":"e_1_2_11_37_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0119079"},{"key":"e_1_2_11_38_1","doi-asserted-by":"publisher","DOI":"10.1113\/EP086637"},{"key":"e_1_2_11_39_1","doi-asserted-by":"publisher","DOI":"10.1016\/S1095-6433(01)00275-6"},{"key":"e_1_2_11_40_1","doi-asserted-by":"publisher","DOI":"10.1155\/2018\/8306154"},{"key":"e_1_2_11_41_1","doi-asserted-by":"publisher","DOI":"10.2165\/00007256-198704060-00004"},{"key":"e_1_2_11_42_1","doi-asserted-by":"publisher","DOI":"10.1152\/ajpheart.1997.272.4.H1609"},{"key":"e_1_2_11_43_1","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00202.2003"},{"key":"e_1_2_11_44_1","doi-asserted-by":"publisher","DOI":"10.1249\/MSS.0000000000001342"},{"key":"e_1_2_11_45_1","doi-asserted-by":"publisher","DOI":"10.1249\/MSS.0b013e31829d24cc"},{"key":"e_1_2_11_46_1","doi-asserted-by":"publisher","DOI":"10.1097\/00005768-200209000-00009"},{"key":"e_1_2_11_47_1","doi-asserted-by":"publisher","DOI":"10.1002\/ajim.23580"},{"key":"e_1_2_11_48_1","doi-asserted-by":"publisher","DOI":"10.1080\/15459624.2024.2406227"},{"key":"e_1_2_11_49_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jtherbio.2025.104077"},{"key":"e_1_2_11_50_1","doi-asserted-by":"publisher","DOI":"10.1080\/15459624.2017.1365151"},{"key":"e_1_2_11_51_1","doi-asserted-by":"publisher","DOI":"10.1016\/S2542-5196(18)30237-7"},{"key":"e_1_2_11_52_1","doi-asserted-by":"publisher","DOI":"10.1080\/23328940.2022.2030634"},{"key":"e_1_2_11_53_1","doi-asserted-by":"publisher","DOI":"10.1139\/apnm-2015-0483"},{"key":"e_1_2_11_54_1","doi-asserted-by":"publisher","DOI":"10.1139\/apnm-2012-0180"},{"key":"e_1_2_11_55_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.buildenv.2012.07.006"},{"key":"e_1_2_11_56_1","unstructured":"F. K.O'Connor Z.Xu K. P.Hutchins et al. \u201cPractical and Accessible Cooling Strategies for Mitigating Exertional Hyperthermia in Low\u2010resource Workplaces: A Systematic Review \u201dTemperature(Austin) (2025) forthcoming."},{"key":"e_1_2_11_57_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00421-024-05610-3"},{"key":"e_1_2_11_58_1","doi-asserted-by":"publisher","DOI":"10.1353\/hpu.2010.0790"},{"key":"e_1_2_11_59_1","doi-asserted-by":"publisher","DOI":"10.1016\/B978-0-444-64074-1.00031-8"},{"key":"e_1_2_11_60_1","doi-asserted-by":"crossref","unstructured":"E. J.Tetzlaff L. G.Ioannou F. K.O'Connor A.Kaltsatou V.Ly andG. P.Kenny \u201cPractical Considerations for Using Personal Cooling Garments for Heat Stress Management in Physically Demanding Occupations: A Systematic Review and Meta\u2010analysis Using Realist Evaluation \u201dAmerican Journal of Industrial Medicine68 no. 1 (2025): 3\u201325.","DOI":"10.1002\/ajim.23672"}],"container-title":["American Journal of Industrial Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/ajim.70015","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/ajim.70015","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/ajim.70015","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,17]],"date-time":"2026-02-17T09:12:30Z","timestamp":1771319550000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/ajim.70015"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,9,3]]},"references-count":59,"journal-issue":{"issue":"11","published-print":{"date-parts":[[2025,11]]}},"alternative-id":["10.1002\/ajim.70015"],"URL":"https:\/\/doi.org\/10.1002\/ajim.70015","archive":["Portico"],"relation":{},"ISSN":["0271-3586","1097-0274"],"issn-type":[{"value":"0271-3586","type":"print"},{"value":"1097-0274","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,9,3]]},"assertion":[{"value":"2025-04-22","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-08-04","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-09-03","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}