{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T11:15:11Z","timestamp":1792062911719,"version":"4.4.0"},"reference-count":47,"publisher":"BMJ","issue":"16","license":[{"start":{"date-parts":[[2025,6,13]],"date-time":"2025-06-13T00:00:00Z","timestamp":1749772800000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000925","name":"National Health and Medical Research Council","doi-asserted-by":"publisher","award":["APP1141127"],"award-info":[{"award-number":["APP1141127"]}],"id":[{"id":"10.13039\/501100000925","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["Br J Sports Med"],"accepted":{"date-parts":[[2025,5,27]]},"published-print":{"date-parts":[[2025,8]]},"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To compare hyperthermia and physiological dehydration risk during exercise heat stress between children of different ages and adults and evaluate an existing adult sweat rate calculator in children.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      68 fit and recreationally active children aged 10\u201316 years (31 girls), and 24 adults aged 18\u201340 years (11 females) completed three separate 45 min treadmill walking\/running trials at different intensities on different days at 30\u00b0C, 40% relative humidity (RH) (WARM) or 40\u00b0C, 30% RH (HOT). Exposures were randomised to elicit intensities scaled to (1) fitness, (2) mass and (3) surface area. Core (gastrointestinal (T\n                      <jats:sub>gi<\/jats:sub>\n                      )) temperature was measured continuously and dehydration determined using body mass changes.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Except for 60% V\u0307O\n                      <jats:sub>2peak<\/jats:sub>\n                      in WARM, in which adults exhibited a greater T\n                      <jats:sub>gi<\/jats:sub>\n                      rise compared with 10\u201313 years, there was no effect of age on T\n                      <jats:sub>gi<\/jats:sub>\n                      during exercise (p\u22650.176). Physiological rates of dehydration were not affected by age in WARM (p\u22650.08) or HOT (p\u22650.08). Mean predicted sweat rate error was +0.08 kg\/hour (95% CIs: \u22120.10, +0.25) across WARM and HOT, and 80.5% of variability in sweating was explained by the adult sweat rate calculator.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Using the most comprehensive paediatric exercise heat stress dataset from a single study to date, we show that children aged 10\u201316 years are at a similar risk of hyperthermia and dehydration as adults during exercise up to 40\u00b0C. This supports recent changes to paediatric sport heat policies that were based on limited data. Practitioners can potentially reduce behavioural dehydration risks from inadequate fluid consumption using an existing adult sweat rate calculator for children.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bjsports-2025-109832","type":"journal-article","created":{"date-parts":[[2025,6,13]],"date-time":"2025-06-13T05:00:20Z","timestamp":1749790820000},"page":"1151-1159","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":21,"title":["Thermoregulation and dehydration in children and youth exercising in extreme heat compared with adults"],"prefix":"10.1136","volume":"59","author":[{"given":"James W","family":"Smallcombe","sequence":"first","affiliation":[{"name":"Heat and Health Research Centre, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thomas H","family":"Topham","sequence":"additional","affiliation":[{"name":"University of Canberra Research Institute for Sport and Exercise, Bruce, Australian Capital Territory, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3433-5151","authenticated-orcid":false,"given":"Harry A","family":"Brown","sequence":"additional","affiliation":[{"name":"University of Canberra Research Institute for Sport and Exercise, Bruce, Australian Capital Territory, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Megan","family":"Tiong","sequence":"additional","affiliation":[{"name":"Heat and Health Research Centre, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Brad","family":"Clark","sequence":"additional","affiliation":[{"name":"Faculty of Health, University of Canberra Research Institute for Sport and Exercise, Bruce, Australian Capital Territory, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carolyn","family":"Broderick","sequence":"additional","affiliation":[{"name":"Heat and Health Research Centre, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia"},{"name":"CHISM, The Childrens Hospital at Westmead, Sydney, New South Wales, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Samuel","family":"Chalmers","sequence":"additional","affiliation":[{"name":"University of South Australia, Adelaide, South Australia, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John","family":"Orchard","sequence":"additional","affiliation":[{"name":"University of Sydney, Sydney, New South Wales, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yorgi","family":"Mavros","sequence":"additional","affiliation":[{"name":"Heat and Health Research Centre, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6266-4246","authenticated-orcid":false,"given":"Julien D","family":"P\u00e9riard","sequence":"additional","affiliation":[{"name":"University of Canberra, Canberra, Australian Capital Territory, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6076-6337","authenticated-orcid":false,"given":"Ollie","family":"Jay","sequence":"additional","affiliation":[{"name":"Heat and Health Research Centre, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2025,6,13]]},"reference":[{"key":"2026012006451433000_59.16.1151.1","unstructured":"UNICEF . 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