The Thermal Environment of the Human Being - A subjective retrospection on methodologies - Gerd Jendritzky1 and George Havenith2 1Meteorological Institute, University of Freiburg, Germany 2Environmental Ergonomics Research Centre, Loughborough University, U.K. gerd.jendritzky@meteo.uni-freiburg.de g.havenith@lboro.ac.uk

Overview Applications (selected examples) Basics in heat exchange Simple Climate Indices Heat Balance Models The Future: Incorporating the Human Provocative remarks

Why? Assessment of the thermal environment: Key issue in human biometeorology!

Applications Public weather service Public health system Precautionary planning Climate impact research

Modelled Heat Load and Observed Mortality 2003, Baden-Württemberg Human Biometeorology Modelled Heat Load and Observed Mortality 2003, Baden-Württemberg christina.koppe@dwd.de DWD 2004

Heat related extra deaths in Europe, August 2003 UTC 13:00 heat load cold stress slight extreme strong moderate comfortable 7000 2045 1400 150 14805 4175 4230

Mortality by Thermal Stress Human Biometeorology 4 13 55 27 F(%) = London (1976 - 2000) Thermal stress category 3 2 1 -1 -2 -3 Mortality (%) 150 140 130 120 110 100 90 1 9 15 46 28 F(%) = Paris (1991 - 1998) Thermal stress category 4 3 2 -1 -2 -3 Mortality 150 140 130 120 110 100 90 Mortality by Thermal Stress (Koppe, 2004) 2 17 28 48 5 F(%) = Lisbon (1981 - 1998) Thermal stress category 4 3 1 -1 -2 -3 Mortality (%) 150 140 130 120 110 100 90 2 17 28 48 5 F(%) = Lisbon (1981 - 1998) Thermal stress category 4 3 1 -1 -2 -3 Mortality (%) 400 350 300 250 200 150 100 50 1 12 18 40 27 F(%) = SW Germany (1968 - 2003) Thermal stress category 4 3 2 -1 -2 -3 Mortality (%) 150 140 130 120 110 100 90 2 13 18 33 31 3 F(%) = Budapest (1972 - 2001) Thermal stress category 4 1 -1 -2 -3 Mortality (%) 150 140 130 120 110 100 90

U height width PT T 42 °C TMRT 38 34 air 30 26 gerd.jendritzky@meteo.uni-freiburg.de

Business Unit Human Biometeorology Berlin frequency of heat load angelika.graetz@dwd.de

The heat wave 2003 in Europe: A unique feature? IPCC WGI, 2001: “Higher maximum temperatures and more hot days over nearly all land areas are very likely” 5 10 15 20 25 30 35 40 45 50 Average summer Tmax [°C] .02 .04 .06 .10 .08 Frequency 1961-1990 (obs) (mod) 2071-2100 2003 Beniston, 2004  Need to adapt

July Delta Perceived Temperature (K), (IS92a-CTL) data: Deutsches Klimarechenzentrum Hamburg; ECHAM4/T106 birger.tinz@dwd.de

Body Core Temperature cold warm

Heat Balance Heat Production Heat Loss

M + W + Q* + QH + QL + QSW + QRe + S = 0 The human heat budget M + W + Q* + QH + QL + QSW + QRe + S = 0 M Metabolic rate W Mechanical power Q* Radiation budget (Tmrt,v) QH Turbulent flux of sensible heat (Ta,v) QL Turbulent flux of latent heat (diffusion water vapour) (e,v) QSW Turbulent flux of latent heat (sweat evaporation) (e,v) QRe Respiratory heat flux (sensible and latent) (Ta,e) S Storage

I Assessment Procedures Simple (mostly two-parameter) thermal indices, „comfort indices“ (> 100 known) Examples: Air temperature Ta Heat index (Ta, RH) Windchill Index (Ta, v) WBGT

Principle Each value of an index must result in the same thermophysiologial effect, regardless of the combinations the meteorological and other environmental input values. No simple index is able to fulfill this requirement!

II Assessment Procedures Weather classifications (holistic approach) (e.g. Kalkstein et al.) Successful in health studies Successful in HHWSs

Avenues of Heat Exchange Direct radiation Sun or other radiation source Reflected Infra-red infra-red Sweat evaporation respiration clothing M External work convection conduction Havenith, 2003

Assessment Procedures Simple index Heat balance model

The Comfort Equation Fanger, 1970

Problems Heat balance models assume “steady state” condition of the human body Models only consider two nodes (core and shell) Physiological response is simplified

Physiological reaction to body cooling Havenith, 2005

Skin Temperature Havenith/ Adidas, 2004

Future Expansion Simple index Heat balance model Human Physiology

Human Physiology Model Control System Brain Controllers Behaviour Environment Heat Exchange Sweating Skin Temperature Threshold + - Core T core skin Skin Blood Flow Shivering Havenith, 2001

Fiala et al., 2001

Universal Thermal Climate Index (UTCI) Future Expansion Simple index Heat balance model Human Physiology model European COST Action 730: Universal Thermal Climate Index (UTCI)

Action 730 on UTCI Fiala et al. 2001

Final Provocative Remarks Temperature related mortality: People die from heat load! Holistic approaches: For what when we basicly know the physiological link! Simple thermal indices: - Former times: Lack of knowledge - Later : No access to computer facilities - Since years : Ignorance of physiological basics Complete heat budget models state-of-the-art Future: Human response related improved models  UTCI Shouldn‘t scientific journals reject manuscripts not based on state-of-the-art?