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Notley SR, Mitchell D, Taylor NAS. A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 2: physiological measurements. Eur J Appl Physiol 2023; 123:2587-2685. [PMID: 37796291 DOI: 10.1007/s00421-023-05284-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 07/14/2023] [Indexed: 10/06/2023]
Abstract
In this, the second of four historical reviews on human thermoregulation during exercise, we examine the research techniques developed by our forebears. We emphasise calorimetry and thermometry, and measurements of vasomotor and sudomotor function. Since its first human use (1899), direct calorimetry has provided the foundation for modern respirometric methods for quantifying metabolic rate, and remains the most precise index of whole-body heat exchange and storage. Its alternative, biophysical modelling, relies upon many, often dubious assumptions. Thermometry, used for >300 y to assess deep-body temperatures, provides only an instantaneous snapshot of the thermal status of tissues in contact with any thermometer. Seemingly unbeknownst to some, thermal time delays at some surrogate sites preclude valid measurements during non-steady state conditions. To assess cutaneous blood flow, immersion plethysmography was introduced (1875), followed by strain-gauge plethysmography (1949) and then laser-Doppler velocimetry (1964). Those techniques allow only local flow measurements, which may not reflect whole-body blood flows. Sudomotor function has been estimated from body-mass losses since the 1600s, but using mass losses to assess evaporation rates requires precise measures of non-evaporated sweat, which are rarely obtained. Hygrometric methods provide data for local sweat rates, but not local evaporation rates, and most local sweat rates cannot be extrapolated to reflect whole-body sweating. The objective of these methodological overviews and critiques is to provide a deeper understanding of how modern measurement techniques were developed, their underlying assumptions, and the strengths and weaknesses of the measurements used for humans exercising and working in thermally challenging conditions.
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Affiliation(s)
- Sean R Notley
- Defence Science and Technology Group, Department of Defence, Melbourne, Australia
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Duncan Mitchell
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
- School of Human Sciences, University of Western Australia, Crawley, Australia
| | - Nigel A S Taylor
- College of Human Ecology, Research Institute of Human Ecology, Seoul National University, Seoul, Republic of Korea.
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Taylor NA, Tipton MJ, Kenny GP. Considerations for the measurement of core, skin and mean body temperatures. J Therm Biol 2014; 46:72-101. [DOI: 10.1016/j.jtherbio.2014.10.006] [Citation(s) in RCA: 228] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 10/24/2014] [Accepted: 10/27/2014] [Indexed: 11/23/2022]
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Taniguchi Y, Sugenoya J, Nishimura N, Iwase S, Matsumoto T, Shimizu Y, Inukai Y, Sato M. Contribution of central versus sweat gland mechanisms to the seasonal change of sweating function in young sedentary males and females. Int J Biometeorol 2011; 55:203-212. [PMID: 20532572 DOI: 10.1007/s00484-010-0325-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Revised: 01/27/2010] [Accepted: 04/18/2010] [Indexed: 05/29/2023]
Abstract
In summer and winter, young, sedentary male (N = 5) and female (N = 7) subjects were exposed to heat in a climate chamber in which ambient temperature (Ta) was raised continuously from 30 to 42°C at a rate of 0.1°C min(-1) at a relative humidity of 40%. Sweat rates (SR) were measured continuously on forearm, chest and forehead together with tympanic temperature (Tty), mean skin temperature (⁻Ts) and mean body temperature ⁻Tb. The rate of sweat expulsions (Fsw) was obtained as an indicator of central sudomotor activity. Tty and ⁻Tb were significantly lower during summer compared with winter in males; SR was not significantly different between summer and winter in males, but was significantly higher during summer in females; SR during winter was higher in males compared with females. The regression line relating Fsw to ⁻Tb shifted significantly from winter to summer in males and females, but the magnitude of the shift was not significantly different between the two subject groups. The regression line relating SR to Fsw was steepened significantly from winter to summer in males and females, and the change in the slope was significantly greater in females than in males. Females showed a lower slope in winter and a similar slope in summer compared to males. It was concluded that sweating function was improved during summer mediated by central sudomotor and sweat gland mechanisms in males and females, and, although the change of sweat gland function from winter to summer was greater in females as compared with males, the level of increased sweat gland function during summer was similar between the two subject groups.
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Affiliation(s)
- Yumiko Taniguchi
- Department of Physiology, Aichi Medical University School of Medicine, Nagakute, Aichi, 480-1195, Japan.
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Abstract
Adverse fetal environments are associated with depression, reduced cognitive ability and increased stress responsiveness in later life, but underlying mechanisms are unknown. Environmental pressures on the fetus, resulting from variations in placental function and maternal nutrition, health and stress might alter neurodevelopment, promoting the development of some brain regions over others. As asymmetry of cerebral activity, with greater right hemisphere activity, has been associated with psychopathology, we hypothesized that regional specialization during fetal life might be reflected persistently in the relative activity of the cerebral hemispheres. We tested this hypothesis in 140 healthy 8-9 year-old children, using tympanic membrane temperature to assess relative blood flow to the cerebral hemispheres at rest and following psychosocial stress (Trier Social Stress Test for Children). Their birth weight and placental weight had already been measured when their mothers took part in a previous study of pregnancy outcomes. We found that children who had a smaller weight at birth had evidence of greater blood flow to the right hemisphere than to the left hemisphere (r = -.09, P = .29 at rest; r = -.18, P = .04 following stress). This finding was strengthened if the children had a relatively low birth weight for their placental weight (r = -.17, P = .05 at rest; r = -.31, P = .0005 following stress). Our findings suggest that lateralization of cerebral activity is influenced persistently by early developmental experiences, with possible consequences for long-term neurocognitive function.
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Affiliation(s)
- Alexander Jones
- Centre for Cardiovascular Imaging, University College London Institute of Child Health, London, United Kingdom.
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Dzarr AA, Kamal M, Baba AA. A comparison between infrared tympanic thermometry, oral and axilla with rectal thermometry in neutropenic adults. Eur J Oncol Nurs 2009; 13:250-4. [DOI: 10.1016/j.ejon.2009.03.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2008] [Revised: 03/12/2009] [Accepted: 03/23/2009] [Indexed: 11/17/2022]
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Inukai Y, Sugenoya J, Kato M, Nishimura N, Nishiyama T, Matsumoto T, Sato M, Ogata A, Taniguchi Y, Osada A. Effects of body posture on local sweating and sudomotor outflow as estimated using sweat expulsion. Auton Neurosci 2005; 119:48-55. [PMID: 15893707 DOI: 10.1016/j.autneu.2005.02.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2004] [Revised: 02/01/2005] [Accepted: 02/03/2005] [Indexed: 11/19/2022]
Abstract
To estimate the effects of changes in body posture on sudomotor function, sweat rates on the forearm, chest and thigh, tympanic temperature (Tty), and skin temperatures were recorded in an upright sitting and a supine position under a hot environment of 40 degrees C Ta and 40% relative humidity for 60 min. Sweat expulsions were identified on sweat rate curves and their rates (Fsw) were calculated. Tty was higher, and its initial fall was greater, in the supine position than in the sitting position. On the forearm and the chest, the regression line relating sweat rate to mean body temperature (Tmb) had a gentler slope in the supine position, whereas on the thigh, it showed a steeper slope. The regression line relating Fsw to Tmb had a steeper slope in the supine position than in the sitting position, suggesting that the gain in the mechanisms for central integration and rhythm-generation was enhanced in the supine position. The parameter of sweat rate divided by Fsw was lower on the forearm and the chest, whereas it was higher on the thigh in the supine position than in the sitting position, suggesting that sudomotor outflow was modified at the spinal cord in association with skin pressure. It was concluded that body posture affects sudomotor functions through both brain and spinal mechanisms.
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Affiliation(s)
- Yoko Inukai
- Department of Physiology, Aichi Medical University School of Medicine, Nagakute, Aichi 480-1195, Japan.
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Abstract
The influence of circadian preference was examined among 56 morning-oriented rehabilitation inpatients with cognitive (n=28) and noncognitive (n=28) impairments. Each individual was tested twice: morning (preferred time) and evening (nonpreferred time); sessions and test batteries were counterbalanced to control for practice effects. Standard measures assessed attention, language, memory, visuospatial, and executive functions. Persons with cognitive impairment showed disproportionate vulnerability to the effects of circadian preference and time of testing, performing more poorly at nonpreferred than preferred times. Substantial effects (eta2 .12 to .48) were found on tests of executive functioning and tasks incorporating similar higher-order demands (e/g/. complex figure copy). Results are supported by tympanic temperature changes during a vigilance task, and index of cerebral blood flow in response to cognitive challenge. Cognitive reserve theory is suggested as an explanation for the differential effects. These findings may have implications for inpatient therapeutic interventions and discharge planning.
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Lockwood C, Conroy-hiller T, Page T. Vital signs: . INT J EVID-BASED HEA 2004; 2:207-30. [DOI: 10.1097/01258363-200407000-00001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Affiliation(s)
- D Falk
- Department of Anthropology, State University of New York at Albany 12222, USA
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Crowder CM, Tempelhoff R, Theard MA, Cheng MA, Todorov A, Dacey RG. Jugular bulb temperature: comparison with brain surface and core temperatures in neurosurgical patients during mild hypothermia. J Neurosurg 1996; 85:98-103. [PMID: 8683289 DOI: 10.3171/jns.1996.85.1.0098] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Blood temperature at the jugular bulb was monitored in 10 patients undergoing neurovascular procedures that used induced mild hypothermia, and its correlation with surface brain, core, and peripheral temperatures was determined. The study was motivated by the difficulty encountered in directly measuring global brain temperature and the poor correlations between various core and peripheral sites temperatures and brain temperature, particularly during deep hypothermia. Although not statistically significant, previous studies have suggested a trend toward higher brain temperatures. Temperatures from the jugular bulb (collected using a No. 5 French Swan-Ganz catheter) as well as from subdural, pulmonary artery, esophagus, tympanic membrane, and bladder sites were analyzed during three surgical conditions: prior to incision, with the dura open, and after closure of the dura. No complications related to placement of the jugular bulb catheter, induced hypothermia, or temperature monitoring were seen. The authors found that jugular bulb temperature was similar to pulmonary artery and esophageal temperatures; although prior to incision it tended to be higher than that found at the pulmonary artery, most commonly by 0.2 degrees C. Surface brain temperature was cooler than all other temperatures (p < 0.05), except that of the tympanic membrane, and was particularly sensitive to environmental variations. Finally, as has been shown by others, bladder temperature lagged substantially behind core temperatures particularly during rapid cooling and rewarming of the patient. In summary, monitoring of jugular bulb temperature is a feasible technique, and temperatures measured in the jugular bulb are similar to core temperatures.
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Affiliation(s)
- C M Crowder
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri, USA
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Umeyama T, Kugimiya T, Ogawa T, Kandori Y, Ishizuka A, Hanaoka K. Changes in cerebral blood flow estimated after stellate ganglion block by single photon emission computed tomography. J Auton Nerv Syst 1995; 50:339-46. [PMID: 7714328 DOI: 10.1016/0165-1838(94)00105-s] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The validity of the hypothesis that the cerebral vasculature is under the control of sympathetic innervation was investigated using brain scintigraphy imaging before and after stellate ganglion block (SGB). The experiment with HM-PAO showed a definite increase in the blood flow of the brain on the block side on both by the dynamic images and the SPECT images. The tympanic temperature (Tty) of the block side decreased significantly after SGB, compared to the unblock side in this study, as had been reported before. This change in Tty coinsided with the increase in cerebral blood flow as mentioned above. This study demonstrated that the cerebral vasculature is under the control of sympathetic innervation, the pathway of which is relayed and/or passes through the stellate ganglion. We conclude that SGB increases intracerebral blood flow and can also exert secondary effects systemically due to CNS blood flow changes as have been previously reported.
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Affiliation(s)
- T Umeyama
- Department of Anesthesiology, University of Tokyo Branch Hospital, Japan
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