1. 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.

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

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

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

5. Modelled Heat Load and Observed Mortality 2003, Baden-Württemberg
Human Biometeorology
Modelled Heat Load and Observed Mortality 2003, Baden-Württemberg
DWD 2004

6. 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

7. Mortality by Thermal Stress
Human Biometeorology 4 13 55 27
F(%) =
London ( )
Thermal stress category 3 2 1 -1 -2 -3
Mortality (%)
150
140
130
120
110
100 90 1 9 15 46 28
F(%) =
Paris ( )
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 ( )
Thermal stress category 4 3 1 -1 -2 -3
Mortality (%)
150
140
130
120
110
100 90 2 17 28 48 5
F(%) =
Lisbon ( )
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 ( )
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 ( )
Thermal stress category 4 1 -1 -2 -3
Mortality (%)
150
140
130
120
110
100 90

8. U height width PT T 42 °C TMRT 38 34 air 30 26

9. Business Unit Human Biometeorology
Berlin
frequency of heat load

10. 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
(obs)
(mod)
2003
Beniston, 2004
 Need to adapt

11. July Delta Perceived Temperature (K), (IS92a-CTL)
data: Deutsches Klimarechenzentrum Hamburg; ECHAM4/T106

12. Body Core Temperature
cold
warm

13. Heat Balance
Heat Production
Heat Loss

14. 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

15. 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

16. 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!

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

18. 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

19. Assessment Procedures
Simple index
Heat balance
model

20. The Comfort Equation
Fanger, 1970

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

23. Physiological reaction to body cooling
Havenith, 2005

24. Skin Temperature
Havenith/ Adidas, 2004

25. Future Expansion Simple index Heat balance model Human Physiology

26. 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

27. Fiala et al., 2001

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

29. Action 730 on UTCI
Fiala et al. 2001

30. 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?