Skip to main content

UTCI-Fiala multi-node model of human heat transfer and temperature regulation


The UTCI-Fiala mathematical model of human temperature regulation forms the basis of the new Universal Thermal Climate Index (UTC). Following extensive validation tests, adaptations and extensions, such as the inclusion of an adaptive clothing model, the model was used to predict human temperature and regulatory responses for combinations of the prevailing outdoor climate conditions. This paper provides an overview of the underlying algorithms and methods that constitute the multi-node dynamic UTCI-Fiala model of human thermal physiology and comfort. Treated topics include modelling heat and mass transfer within the body, numerical techniques, modelling environmental heat exchanges, thermoregulatory reactions of the central nervous system, and perceptual responses. Other contributions of this special issue describe the validation of the UTCI-Fiala model against measured data and the development of the adaptive clothing model for outdoor climates.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5


  • Aschoff VJ, Wever R (1958) Kern und Schale im Wärmehaushalt des Menschen. Naturwissenschaften 45:477–485

    Article  Google Scholar 

  • ASHRAE (2004) ANSI/ASHRAE standard 55: thermal environmental conditions for human occupancy. American Society of Heating, Refrigeration and Air-Conditioning Engineers, Inc, Atlanta

    Google Scholar 

  • Azer NZ, Hsu S (1977) The prediction of thermal sensation from a simple model of human physiological regulatory response. ASHRAE Trans 83:88–102

    Google Scholar 

  • Burton AC (1937) The application of the theory of heat flow to the study of energy metabolism. J Nutrition:487–533

  • Bröde P, Fiala D, Blazejczyk K, Holmér I, Jendritzky G, Kampmann B, Tinz B, Havenith G (2011a) Deriving the Operational Procedure for the Universal Thermal Climate Index UTCI. Int J Biometeorol

  • Bröde P, Krüger EL, Rossi FA, Fiala D (2011b) Predicting urban outdoor thermal comfort by the universal thermal climate index UTCI – A case study in southern Brazil. Int J Biometeorol

  • Crawshaw LI, Nadel ER, Stolwijk JAJ, Stamford BA (1975) Effect of local cooling on sweating rate and cold sensation. Pflügers Arch 354:19–27

    Article  CAS  Google Scholar 

  • Fanger PO (1973) Thermal comfort - analysis and applications in environmental engineering. McGraw-Hill, New York

    Google Scholar 

  • Fiala D (1998) Dynamic simulation of human heat transfer and thermal comfort. PhD thesis, De Montfort University, UK

  • Fiala D, Lomas KJ, Stohrer M (1999) A computer model of human thermoregulation for a wide range of environmental conditions: the passive system. J Appl Physiol 87:1957–1972

    CAS  Google Scholar 

  • Fiala D, Lomas KJ, Stohrer M (2001) Computer prediction of human thermoregulatory and temperature responses to a wide range of environmental conditions. Int J Biometeorol 45:143–159

    Article  CAS  Google Scholar 

  • Fiala D, Lomas KJ, Stohrer M (2003) First principles modelling of thermal sensation responses in steady state and transient boundary conditions. ASHRAE Trans 109(1):179–186

    Google Scholar 

  • Fiala D, Bunzl A, Lomas KJ, Cropper PC, Schlenz D (2004) A new simulation system for predicting human thermal and perceptual responses in vehicles. In: Schlenz D (ed) PKW-Klimatisierung III: Klimakonzepte, Regelungsstrategien und Entwicklungsmethoden. Expert Verlag Renningen, Haus der Technik Fachbuch Band 27: 147–162

  • Fiala D, Psikuta A, Jendritzky G, Paulke S, Nelson DA, van Marken Lichtenbelt WD, Frijns AJH (2010) Physiological modeling for technical, clinical and research applications. Front Biosci S2:939–968

    Article  Google Scholar 

  • Gagge AP, Fobelets AP, Berglund PE (1986) A standard predictive index of human response to the thermal environment. ASHRAE Trans 92:709–731

    Google Scholar 

  • Gordon RG, Roemer RB, Horvath SM (1976) A mathematical model of the human temperature regulatory system - transient cold exposure response. IEEE Trans Biomed Eng 23:434–444

    Article  CAS  Google Scholar 

  • Havenith G, Fiala D, Blazejczyk K, Richards M, Bröde P, Holmér I, Rintamäki H, Benshabat Y, Jendritzky G (2011) The UTCI-Clothing Model. Int J Biometeorol

  • Huizenga C, Zhang H, Arens E (2001) A model of human physiology and comfort for assessing complex thermal environments. Build Environ 36:691–699

    Article  Google Scholar 

  • ISO 7730 (2005) Ergonomics of the thermal environment - Analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria. International Organisation for Standardisation, Geneve

    Google Scholar 

  • Jones BW, Ogawa Y (1992) Transient interaction between the human and the thermal environment. ASHRAE Trans 98:189–196

    Google Scholar 

  • Kampmann B, Bröde P, Fiala D (2011) Physiological responses to temperature and humidity compared to the assessment by UTCI, WGBT and PHS. Int J Biometeorol

  • Kubaha K, Fiala D, Toftum J, Taki AH (2004) Human projected area factors for detailed direct and diffuse solar radiation analysis. Int J Biometeorol 49:113–129

    Article  CAS  Google Scholar 

  • Kubaha K (2005) Asymmetric radiation and human thermal comfort: PhD thesis, De Montfort University, UK

  • McCullough EA, Jones BW, Huck J (1985) A comprehensive data base for estimating clothing insulation. ASHRAE Trans 92:29–47

    Google Scholar 

  • McCullough EA, Jones BW, Tamura T (1989) A data base for determining the evaporative resistance of clothing. ASHRAE Trans 95:316–328

    Google Scholar 

  • Nadel ER, Bullard RW, Stolwijk JAJ (1971) Importance of skin temperature in the regulation of sweating. J Appl Physiol 31:80–87

    CAS  Google Scholar 

  • Nadel ER, Mitchell JW, Stolwijk JAJ (1973) Differential thermal sensitivity in the human skin. Pflügers Arch 340:71–76

    Article  CAS  Google Scholar 

  • Oke TR (1987) Boundary layer climates. Routledge, London

    Google Scholar 

  • Pennes HH (1948) Analysis of tissue and arterial blood temperatures in the resting human forearm. J Appl Physiol 1:93–122

    CAS  Google Scholar 

  • Psikuta A Fiala D, Laschewski G, Jendritzky G, Richards M, Blazejczyk K, Mekjavic I, Rintamäki H, Havenith G, de Dear R (2011) Evaluation of the Fiala multi-node thermophysiological model for UTCI application. Int J Biometeorol

  • Richards M, Fiala D (2004) Modelling fire-fighter responses to exercise and asymmetric IR-radiation using a dynamic multi-mode model of human physiology and results from the Sweating Agile thermal Manikin (SAM). Eur J Appl Physiol 92:649–653

    Article  CAS  Google Scholar 

  • Stolwijk JAJ (1971) A mathematical model of physiological temperature regulation in man. NASA contractor report, NASA CR-1855, Washington DC

  • Tanabe S, Kobayashi K, Nakano J, Ozeki Y, Konishi M (2002) Evaluation of thermal comfort using combined multi-node thermoregulation (65MN) and radiation models and computational fluid dynamics (CFD). Energ Buildings 34:637–646

    Article  Google Scholar 

  • Wang X-L (1990) Convective heat losses from segments of the human body. Climate Buildings 3:8–14

    Google Scholar 

  • Weinbaum S, Jiji LM, Lemons DE (1984) Theory and experiment for the effect of vascular microstructure on surface tissue heat transfer - part I: anatomical foundation and model conceptualization. ASME J Biomech Eng 106:321–330

    Article  CAS  Google Scholar 

  • Wissler EH (1985) Mathematical simulation of human thermal behavior using whole body models. In: Shitzer A, Eberhart RC (eds) Heat transfer in medicine and biology – analysis and applications. Plenum, New York, pp 325–373

    Google Scholar 

Download references


The authors express their gratitude to Deutscher Akademischer Austauschdienst (DAAD) for British-German Academic Research Collaboration and COST Action 730: “Toward a universal thermal climate index UTCI for assessing the thermal environment of the human being” for travel funding; COST is supported by the EU RTD Framework Programme.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Dusan Fiala.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Fiala, D., Havenith, G., Bröde, P. et al. UTCI-Fiala multi-node model of human heat transfer and temperature regulation. Int J Biometeorol 56, 429–441 (2012).

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Physiological simulation
  • Human exposure
  • Outdoor environment
  • Multi-segmental model
  • Thermoregulatory system