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Human responses in heat – comparison of the Predicted Heat Strain and the Fiala multi-node model for a case of intermittent work.

Lundgren Kownacki, Karin LU ; Martinez, Natividad; Johansson, Bo; Psikuta, Agnes; Annaheim, Simon and Kuklane, Kalev LU (2017) In Journal of Thermal Biology
Abstract
Two mathematical models of human thermal regulation include the rational Predicted Heat Strain (PHS) and the thermophysiological model by Fiala. The approaches of the models are different, however, they both aim at providing predictions of the thermophysiological responses to thermal environments of an average person. The aim of this study was to compare and analyze predictions of the two models against experimental data. The analysis also includes a gender comparison. The experimental data comprised of ten participants (5 males, 5 females, average anthropometric values were used as input) conducting an intermittent protocol of rotating tasks (cycling, stacking, stepping and arm crank) of moderate metabolic activities (134-291 W/m2) with... (More)
Two mathematical models of human thermal regulation include the rational Predicted Heat Strain (PHS) and the thermophysiological model by Fiala. The approaches of the models are different, however, they both aim at providing predictions of the thermophysiological responses to thermal environments of an average person. The aim of this study was to compare and analyze predictions of the two models against experimental data. The analysis also includes a gender comparison. The experimental data comprised of ten participants (5 males, 5 females, average anthropometric values were used as input) conducting an intermittent protocol of rotating tasks (cycling, stacking, stepping and arm crank) of moderate metabolic activities (134-291 W/m2) with breaks in-between in a controlled environmental condition (34°C, 60% RH). The validation consisted of the predictions’ comparison against experimental data from 2.5 hours of data of rectal temperature and mean skin temperature based on contact thermometry from four body locations. The PHS model over-predicted rectal temperatures during the first activity for males and the cooling effectiveness of sweat in the recovery periods, for both males and females. As a result, the PHS simulation underestimated the thermal strain in this context. The Fiala model accurately predicted the rectal temperature throughout the exposure. The fluctuation of the experimental mean skin temperature was not reflected in any of the models. However, the PHS simulation model showed better agreement than the Fiala model. As both models predicted responses more accurately for males than females, we suggest that in future development of the models it is important to take this result into account. The paper further discusses possible sources of the observed discrepancies and concludes with some suggestions for modifications. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
epub
subject
keywords
Heat stress; Exposure limit prediction; Thermal physiological model; Work capacity; Sex difference; Activity variation
in
Journal of Thermal Biology
publisher
Elsevier
external identifiers
  • scopus:85019993136
  • wos:000414878900007
ISSN
0306-4565
DOI
10.1016/j.jtherbio.2017.05.006
language
English
LU publication?
yes
id
96b5092c-8b8f-4353-8aff-936055c1708e
date added to LUP
2017-05-29 14:43:41
date last changed
2018-01-16 13:19:55
@article{96b5092c-8b8f-4353-8aff-936055c1708e,
  abstract     = {Two mathematical models of human thermal regulation include the rational Predicted Heat Strain (PHS) and the thermophysiological model by Fiala. The approaches of the models are different, however, they both aim at providing predictions of the thermophysiological responses to thermal environments of an average person. The aim of this study was to compare and analyze predictions of the two models against experimental data. The analysis also includes a gender comparison. The experimental data comprised of ten participants (5 males, 5 females, average anthropometric values were used as input) conducting an intermittent protocol of rotating tasks (cycling, stacking, stepping and arm crank) of moderate metabolic activities (134-291 W/m2) with breaks in-between in a controlled environmental condition (34°C, 60% RH). The validation consisted of the predictions’ comparison against experimental data from 2.5 hours of data of rectal temperature and mean skin temperature based on contact thermometry from four body locations. The PHS model over-predicted rectal temperatures during the first activity for males and the cooling effectiveness of sweat in  the recovery periods, for both males and females. As a result, the PHS simulation underestimated the thermal strain in this context. The Fiala model accurately predicted the rectal temperature throughout the exposure. The fluctuation of the experimental mean skin temperature was not reflected in any of the models. However, the PHS simulation model showed better agreement than the Fiala model. As both models predicted responses more accurately for males than females, we suggest that in future development of the models it is important to take this result into account. The paper further discusses possible sources of the observed discrepancies and concludes with some suggestions for modifications.},
  author       = {Lundgren Kownacki, Karin and Martinez, Natividad and Johansson, Bo and Psikuta, Agnes and Annaheim, Simon and Kuklane, Kalev},
  issn         = {0306-4565},
  keyword      = {Heat stress; Exposure limit prediction; Thermal physiological model; Work capacity; Sex difference; Activity variation},
  language     = {eng},
  month        = {05},
  publisher    = {Elsevier},
  series       = {Journal of Thermal Biology},
  title        = {Human responses in heat – comparison of the Predicted Heat Strain and the Fiala multi-node model for a case of intermittent work.},
  url          = {http://dx.doi.org/10.1016/j.jtherbio.2017.05.006},
  year         = {2017},
}