{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T16:17:04Z","timestamp":1753892224903,"version":"3.41.2"},"reference-count":44,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2022,3,4]],"date-time":"2022-03-04T00:00:00Z","timestamp":1646352000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Physiol."],"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>Indirect core body temperature (CBT) monitoring from skin sensors is gaining attention for in-field applications thanks to non-invasivity, portability, and easy probe positioning. Among skin sensors, heat-flux devices, such as the so-called Double Sensor (DS), have demonstrated reliability under various experimental and clinical conditions. Still, their accuracy at low ambient temperatures is unknown. In this randomized cross-over trial, we tested the effects of cold temperature exposition on DS performance in tracking CBT.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Twenty-one participants were exposed to a warm (23.2\u2009\u00b1\u20090.4\u00b0C) and cold (\u221218.7\u2009\u00b1\u20091.0\u00b0C) room condition for 10\u2009min, following a randomized cross-over design. The accuracy of the DS to estimate CBT in both settings was assessed by quantitative comparison with esophageal (reference) and tympanic (comparator) thermometers, using Bland\u2013Altman and correlation analyses (Pearson\u2019s correlation coefficient, <jats:italic>r<\/jats:italic>, and Lin\u2019s concordance correlation coefficient, <jats:italic>CCC<\/jats:italic>).<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>In the warm room setting, the DS showed a moderate agreement with the esophageal sensor [bias\u2009=\u20090.09 (\u22121.51; 1.69) \u00b0C, <jats:italic>r<\/jats:italic>\u2009=\u20090.40 (<jats:italic>p<\/jats:italic>\u2009=\u20090.069), CCC\u2009=\u20090.22 (\u22120.006; 0.43)] and tympanic sensor [bias\u2009=\u20092.74 (1.13; 4.35) \u00b0C, <jats:italic>r<\/jats:italic>\u2009=\u20090.54 (<jats:italic>p<\/jats:italic>\u2009&amp;lt;\u20090.05), CCC\u2009=\u20090.09 (0.008; 0.16)]. DS accuracy significantly deteriorated in the cold room setting, where DS temperature overestimated esophageal temperature [bias\u2009=\u20092.16 (\u22120.89; 5.22) \u00b0C, <jats:italic>r<\/jats:italic>\u2009=\u20090.02 (0.94), CCC\u2009=\u20090.002 (\u22120.05; 0.06)]. Previous exposition to the cold influenced temperature values measured by the DS in the warm room setting, where significant differences (<jats:italic>p<\/jats:italic>\u2009&amp;lt;\u20090.00001) in DS temperature were observed between randomization groups.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>DS accuracy is influenced by environmental conditions and previous exposure to cold settings. These results suggest the present inadequacy of the DS device for in-field applications in low-temperature environments and advocate further technological advancements and proper sensor insulation to improve performance in these conditions.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fphys.2022.830059","type":"journal-article","created":{"date-parts":[[2022,3,4]],"date-time":"2022-03-04T10:19:50Z","timestamp":1646389190000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Low Ambient Temperature Exposition Impairs the Accuracy of a Non-invasive Heat-Flux Thermometer"],"prefix":"10.3389","volume":"13","author":[{"given":"Michela","family":"Mas\u00e8","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andreas","family":"Werner","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gabriel","family":"Putzer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Giovanni","family":"Avancini","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marika","family":"Falla","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hermann","family":"Brugger","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alessandro","family":"Micarelli","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Giacomo","family":"Strapazzon","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2022,3,4]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"301","DOI":"10.2147\/MDER.S109904","article-title":"Accuracy and precision of four common peripheral temperature measurement methods in intensive care patients","volume":"9","author":"Asadian","year":"2016","journal-title":"Med Dev."},{"key":"ref2","doi-asserted-by":"publisher","first-page":"477","DOI":"10.1007\/BF00635546","article-title":"Kern und Schale im W\u00e4rmehaushalt des Menschen","volume":"45","author":"Aschoff","year":"1958","journal-title":"Naturwissenschaften"},{"key":"ref3","first-page":"111","article-title":"Cranial measurements of internal temperature in man","volume-title":"Temperature \u2013 Its Measurement and Control in Science and Industry.","author":"Benzinger","year":"1963"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"47","DOI":"10.1016\/0306-4565(89)90029-6","article-title":"Tympanic temperature is a core temperature in humans","volume":"14","author":"Brinnel","year":"1989","journal-title":"J. Therm. Biol."},{"key":"ref5","doi-asserted-by":"publisher","first-page":"63","DOI":"10.1016\/j.autneu.2016.02.009","article-title":"Human physiological responses to cold exposure: acute responses and acclimatization to prolonged exposure","volume":"196","author":"Castellani","year":"2016","journal-title":"Auton. Neurosci."},{"key":"ref6","first-page":"8","article-title":"A new technique for monitoring the deep body temperature in man from the intact skin surface","volume":"212","author":"Fox","year":"1971","journal-title":"J. Physiol."},{"key":"ref7","doi-asserted-by":"publisher","first-page":"266","DOI":"10.1016\/s0964-3397(97)80425-9","article-title":"Core body temperature measurement: a comparison of axilla, tympanic membrane and pulmonary artery blood temperature","volume":"13","author":"Fulbrook","year":"1997","journal-title":"Intensive Crit. Care Nurs."},{"key":"ref8","doi-asserted-by":"publisher","first-page":"157","DOI":"10.4085\/1062-6050-45.2.157","article-title":"Aural canal, esophageal, and rectal temperatures during exertional heat stress and the subsequent recovery period","volume":"45","author":"Gagnon","year":"2010","journal-title":"J. Athl. Train."},{"key":"ref9","first-page":"32","article-title":"Reviewing the effectiveness of tympanic thermometers","volume":"100","author":"Gallimore","year":"2004","journal-title":"Nurs. Times"},{"key":"ref10","doi-asserted-by":"publisher","first-page":"191","DOI":"10.1016\/j.circv.2019.06.002","article-title":"Intra-operative temperature monitoring with two non-invasive devices (3M Spoton\u00ae and Dr\u00e4ger Tcore\u00ae) in comparison with the swan-Ganz catheter","volume":"26","author":"G\u00f3mez-Romero","year":"2019","journal-title":"Cirug\u00eda Cardio."},{"key":"ref11","doi-asserted-by":"publisher","first-page":"297","DOI":"10.1016\/j.jtherbio.2008.03.004","article-title":"A non-invasive device to continuously determine heat strain in humans","volume":"33","author":"Gunga","year":"2008","journal-title":"J. Therm. Biol."},{"key":"ref12","doi-asserted-by":"publisher","first-page":"S63","DOI":"10.1016\/j.resp.2009.04.005","article-title":"The double sensor-A non-invasive device to continuously monitor core temperature in humans on earth and in space","volume":"169","author":"Gunga","year":"2009","journal-title":"Respir. Physiol. Neurobiol."},{"key":"ref13","doi-asserted-by":"publisher","first-page":"e0150759","DOI":"10.1371\/journal.pone.0150759","article-title":"Zero-heat-flux thermometry for non-invasive measurement of Core body temperature in pigs","volume":"11","author":"Guschlbauer","year":"2016","journal-title":"PLoS One"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"345","DOI":"10.1002\/(SICI)1096-8644(199903)108:3<345::AID-AJPA9>3.0.CO;2-S","article-title":"The elusive diploic veins: anthropological and anatomical perspective","volume":"108","author":"Hershkovitz","year":"1999","journal-title":"Am. J. Phys. Anthropol."},{"key":"ref15","doi-asserted-by":"publisher","first-page":"666908","DOI":"10.3389\/fmed.2021.666908","article-title":"Measuring Core body temperature using a non-invasive, disposable double-sensor During targeted temperature Management in Post-cardiac Arrest Patients","volume":"8","author":"Janke","year":"2021","journal-title":"Front. Med."},{"key":"ref16","doi-asserted-by":"publisher","first-page":"1190","DOI":"10.1007\/s12630-013-0047-z","article-title":"The accuracy of a disposable noninvasive core thermometer","volume":"60","author":"Kimberger","year":"2013","journal-title":"Can. J. Anaesth."},{"key":"ref17","doi-asserted-by":"publisher","first-page":"226","DOI":"10.1093\/bja\/aep134","article-title":"Accuracy and precision of a novel non-invasive core thermometer","volume":"103","author":"Kimberger","year":"2009","journal-title":"Br. J. Anaesth."},{"key":"ref18","doi-asserted-by":"publisher","first-page":"483","DOI":"10.1016\/B978-0-444-64074-1.00030-6","article-title":"Brain temperature: from physiology and pharmacology to neuropathology","volume":"157","author":"Kiyatkin","year":"2018","journal-title":"Handb. Clin. Neurol."},{"key":"ref19","doi-asserted-by":"publisher","first-page":"181","DOI":"10.1007\/BF02363069","article-title":"Improvement of deep body thermometer for man","volume":"3","author":"Kobayashi","year":"1975","journal-title":"Ann. Biomed. Eng."},{"key":"ref20","doi-asserted-by":"publisher","first-page":"392","DOI":"10.1016\/j.wem.2021.04.005","article-title":"The wind-chill index","volume":"32","author":"Lankford","year":"2021","journal-title":"Wilderness Environ. Med."},{"key":"ref21","first-page":"347","article-title":"Human thermoregulation and measurement of body temperature in exercise and clinical settings","volume":"37","author":"Lim","year":"2008","journal-title":"Ann. Acad. Med."},{"key":"ref22","doi-asserted-by":"publisher","first-page":"43","DOI":"10.1186\/s40560-021-00558-4","article-title":"Insight into the use of tympanic temperature during target temperature management in emergency and critical care: a scoping review","volume":"9","author":"Mas\u00e8","year":"2021","journal-title":"J. Intensive Care"},{"key":"ref23","doi-asserted-by":"publisher","first-page":"568886","DOI":"10.3389\/fphys.2020.568886","article-title":"Hearables: new perspectives and pitfalls of in-ear devices for physiological monitoring. A scoping Review","volume":"11","author":"Mas\u00e8","year":"2020","journal-title":"Front. Physiol."},{"key":"ref24","doi-asserted-by":"publisher","first-page":"17","DOI":"10.1016\/j.jtherbio.2017.03.007","article-title":"Measuring core body temperature with a non-invasive sensor","volume":"66","author":"Mazgaoker","year":"2017","journal-title":"J. Therm. Biol."},{"key":"ref25","doi-asserted-by":"publisher","first-page":"242","DOI":"10.1080\/03091900600711415","article-title":"The vagaries of ear temperature assessment","volume":"30","author":"McCarthy","year":"2006","journal-title":"J. Med. Eng. Technol."},{"key":"ref26","doi-asserted-by":"publisher","first-page":"658707","DOI":"10.3389\/fphys.2021.658707","article-title":"Long-term bed rest delays the circadian phase of Core body temperature","volume":"12","author":"Mendt","year":"2021","journal-title":"Front. Physiol."},{"key":"ref27","doi-asserted-by":"publisher","first-page":"666","DOI":"10.1080\/07420528.2016.1224241","article-title":"Circadian rhythms in bed rest: monitoring core body temperature via heat-flux approach is superior to skin surface temperature","volume":"34","author":"Mendt","year":"2017","journal-title":"Chronobiol. Int."},{"key":"ref28","doi-asserted-by":"publisher","first-page":"879","DOI":"10.2165\/00007256-200232140-00001","article-title":"Core temperature measurement: methods and current insights","volume":"32","author":"Moran","year":"2002","journal-title":"Sports Med."},{"key":"ref29","doi-asserted-by":"publisher","first-page":"271","DOI":"10.1097\/00000542-198303000-00014","article-title":"Deep body thermometry during general anesthesia","volume":"58","author":"Muravchick","year":"1983","journal-title":"Anesthesiology"},{"key":"ref30","first-page":"623","article-title":"Head-temperature effects on physiology, comfort, and performance during hyperthermia","volume":"53","author":"Nunneley","year":"1982","journal-title":"Aviat. Space Environ. Med."},{"key":"ref31","doi-asserted-by":"publisher","first-page":"768","DOI":"10.1093\/bja\/aet217","article-title":"Temporal and spatial dispersion of human body temperature during deep hypothermia","volume":"111","author":"Opatz","year":"2013","journal-title":"Br. J. Anaesth."},{"key":"ref32","doi-asserted-by":"publisher","first-page":"811","DOI":"10.1213\/00000539-199310000-00027","article-title":"The direction dependence of thermoregulatory vasoconstriction during isoflurane\/epidural anesthesia in humans","volume":"77","author":"Ozaki","year":"1993","journal-title":"Anesth. Analg."},{"key":"ref33","doi-asserted-by":"publisher","first-page":"637","DOI":"10.1007\/s00484-009-0299-z","article-title":"Model for understanding thermal hysteresis during heat stress: a matter of direction","volume":"54","author":"Parkhurst","year":"2010","journal-title":"Int. J. Biometeorol."},{"key":"ref34","doi-asserted-by":"publisher","first-page":"583","DOI":"10.1093\/bja\/71.4.583","article-title":"Deep body temperature during the warming phase of cardiopulmonary bypass","volume":"71","author":"Sakuragi","year":"1993","journal-title":"Br. J. Anaesth."},{"key":"ref35","doi-asserted-by":"publisher","first-page":"638","DOI":"10.1096\/fasebj.7.8.8500688","article-title":"Perianesthetic thermoregulation and heat balance in humans","volume":"7","author":"Sessler","year":"1993","journal-title":"FASEB J."},{"key":"ref36","doi-asserted-by":"publisher","first-page":"72","DOI":"10.1186\/s13049-015-0148-5","article-title":"The impact of environmental factors in pre-hospital thermistor-based tympanic temperature measurement: a pilot field study","volume":"23","author":"Skaiaa","year":"2015","journal-title":"Scand. J. Trauma Resusc. Emerg. Med."},{"key":"ref37","doi-asserted-by":"publisher","first-page":"16180","DOI":"10.1038\/s41598-017-15560-w","article-title":"Increased core body temperature in astronauts during long-duration space missions","volume":"7","author":"Stahn","year":"2017","journal-title":"Sci. Rep."},{"key":"ref38","doi-asserted-by":"publisher","first-page":"104","DOI":"10.1089\/ham.2014.1008","article-title":"Pre-hospital core temperature measurement in accidental and therapeutic hypothermia","volume":"15","author":"Strapazzon","year":"2014","journal-title":"High Alt. Med. Biol."},{"key":"ref39","doi-asserted-by":"publisher","first-page":"90","DOI":"10.1186\/s13049-015-0172-5","article-title":"Influence of low ambient temperature on epitympanic temperature measurement: a prospective randomized clinical study","volume":"23","author":"Strapazzon","year":"2015","journal-title":"Scand. J. Trauma Resusc. Emerg. Med."},{"key":"ref40","doi-asserted-by":"publisher","first-page":"72","DOI":"10.1016\/j.jtherbio.2014.10.006","article-title":"Considerations for the measurement of core, skin and mean body temperatures","volume":"46","author":"Taylor","year":"2014","journal-title":"J. Therm. Biol."},{"key":"ref41","doi-asserted-by":"publisher","first-page":"559","DOI":"10.1088\/0967-3334\/32\/5\/005","article-title":"Non-invasive continuous core temperature measurement by zero heat flux","volume":"32","author":"Teunissen","year":"2011","journal-title":"Physiol. Meas."},{"year":"2013","author":"Werner","key":"ref42"},{"key":"ref43","doi-asserted-by":"publisher","first-page":"2381","DOI":"10.1007\/s00421-013-2674-z","article-title":"Relationship between core temperature, skin temperature, and heat flux during exercise in heat","volume":"113","author":"Xu","year":"2013","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref44","doi-asserted-by":"publisher","first-page":"861","DOI":"10.1016\/j.resuscitation.2010.03.018","article-title":"Non-invasive continuous cerebral temperature monitoring in patients treated with mild therapeutic hypothermia: an observational pilot study","volume":"81","author":"Zeiner","year":"2010","journal-title":"Resuscitation"}],"container-title":["Frontiers in Physiology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fphys.2022.830059\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,3,4]],"date-time":"2022-03-04T10:19:55Z","timestamp":1646389195000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fphys.2022.830059\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,3,4]]},"references-count":44,"alternative-id":["10.3389\/fphys.2022.830059"],"URL":"https:\/\/doi.org\/10.3389\/fphys.2022.830059","relation":{},"ISSN":["1664-042X"],"issn-type":[{"type":"electronic","value":"1664-042X"}],"subject":[],"published":{"date-parts":[[2022,3,4]]},"article-number":"830059"}}