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1.
Psikuta A Fiala D Laschewski G Jendritzky G Richards M Błażejczyk K Mekjavič I Rintamäki H de Dear R Havenith G 《International journal of biometeorology》2012,56(3):443-460
The important requirement that COST Action 730 demanded of the physiological model to be used for the Universal Thermal Climate
Index (UTCI) was its capability of accurate simulation of human thermophysiological responses across a wide range of relevant
environmental conditions, such as conditions corresponding to the selection of all habitable climates and their seasonal changes,
and transient conditions representing the temporal variation of outdoor conditions. In the first part of this study, available
heat budget/two-node models and multi-node thermophysiological models were evaluated by direct comparison over a wide spectrum
of climatic conditions. The UTCI-Fiala model predicted most reliably the average human thermal response, as shown by least
deviations from physiologically plausible responses when compared to other models. In the second part of the study, this model
was subjected to extensive validation using the results of human subject experiments for a range of relevant (steady-state
and transient) environmental conditions. The UTCI-Fiala multi-node model proved its ability to predict adequately the human
physiological response for a variety of moderate and extreme conditions represented in the COST 730 database. The mean skin
and core temperatures were predicted with average root-mean-square deviations of 1.35 ± 1.00°C and 0.32 ± 0.20°C, respectively. 相似文献
2.
Bröde P Fiala D Błażejczyk K Holmér I Jendritzky G Kampmann B Tinz B Havenith G 《International journal of biometeorology》2012,56(3):481-494
The Universal Thermal Climate Index (UTCI) aimed for a one-dimensional quantity adequately reflecting the human physiological
reaction to the multi-dimensionally defined actual outdoor thermal environment. The human reaction was simulated by the UTCI-Fiala
multi-node model of human thermoregulation, which was integrated with an adaptive clothing model. Following the concept of
an equivalent temperature, UTCI for a given combination of wind speed, radiation, humidity and air temperature was defined
as the air temperature of the reference environment, which according to the model produces an equivalent dynamic physiological
response. Operationalising this concept involved (1) the definition of a reference environment with 50% relative humidity
(but vapour pressure capped at 20 hPa), with calm air and radiant temperature equalling air temperature and (2) the development
of a one-dimensional representation of the multivariate model output at different exposure times. The latter was achieved
by principal component analyses showing that the linear combination of 7 parameters of thermophysiological strain (core, mean
and facial skin temperatures, sweat production, skin wettedness, skin blood flow, shivering) after 30 and 120 min exposure
time accounted for two-thirds of the total variation in the multi-dimensional dynamic physiological response. The operational
procedure was completed by a scale categorising UTCI equivalent temperature values in terms of thermal stress, and by providing
simplified routines for fast but sufficiently accurate calculation, which included look-up tables of pre-calculated UTCI values
for a grid of all relevant combinations of climate parameters and polynomial regression equations predicting UTCI over the
same grid. The analyses of the sensitivity of UTCI to humidity, radiation and wind speed showed plausible reactions in the
heat as well as in the cold, and indicate that UTCI may in this regard be universally useable in the major areas of research
and application in human biometeorology. 相似文献
3.
Huang J 《International journal of biometeorology》2007,51(5):375-382
Current thermal comfort indices do not take into account the effects of wind and body movement on the thermal resistance and
vapor resistance of clothing. This may cause public health problem, e.g. cold-related mortality. Based on the energy balance
equation and heat exchanges between a clothed body and the outdoor environment, a mathematical model was developed to determine
the air temperature at which an average adult, wearing a specific outdoor clothing and engaging in a given activity, attains
thermal comfort under outdoor environment condition. The results indicated low clothing insulation, less physical activity
and high wind speed lead to high air temperature prediction for thermal comfort. More accurate air temperature prediction
is able to prevent wearers from hypothermia under cold conditions. 相似文献
4.
Jennifer K. Vanos Jon S. Warland Terry J. Gillespie Natasha A. Kenny 《International journal of biometeorology》2010,54(4):319-334
This review comprehensively examines scientific literature pertaining to human physiology during exercise, including mechanisms
of heat formation and dissipation, heat stress on the body, the importance of skin temperature monitoring, the effects of
clothing, and microclimatic measurements. This provides a critical foundation for microclimatologists and biometeorologists
in the understanding of experiments involving human physiology. The importance of the psychological aspects of how an individual
perceives an outdoor environment are also reviewed, emphasizing many factors that can indirectly affect thermal comfort (TC).
Past and current efforts to develop accurate human comfort models are described, as well as how these models can be used to
develop resilient and comfortable outdoor spaces for physical activity. Lack of suitable spaces plays a large role in the
deterioration of human health due to physical inactivity, leading to higher rates of illness, heart disease, obesity and heat-related
casualties. This trend will continue if urban designers do not make use of current knowledge of bioclimatic urban design,
which must be synthesized with physiology, psychology and microclimatology. Increased research is required for furthering
our knowledge on the outdoor human energy balance concept and bioclimatic design for health and well-being in urban areas. 相似文献
5.
Dessai S 《International journal of biometeorology》2002,47(1):6-12
Global climate change will have direct impacts on human health, including increased mortality due to heat stress and heat waves. An empirical-statistical model for heat stress is constructed for the city of Lisbon using the June-August months of the observational period 1980-1998. The model uses the regression of an aggregate dose-response relationship between maximum temperature and excess heat-related deaths, based on the difference between observed and expected deaths. The model is validated by correlation and residual analysis. The mean annual heat-related mortality for the period 1980-1998 was between 5.4 and 6 deaths per 100,000 depending on the method used to calculate expected deaths. Both validation methods show that the model has a moderate to high accuracy in modelling heat-related deaths compared to the observed record. 相似文献
6.
UTCI—Why another thermal index? 总被引:2,自引:0,他引:2
Existing procedures for the assessment of the thermal environment in the fields of public weather services, public health
systems, precautionary planning, urban design, tourism and recreation and climate impact research exhibit significant shortcomings.
This is most evident for simple (mostly two-parameter) indices, when comparing them to complete heat budget models developed
since the 1960s. ISB Commission 6 took up the idea of developing a Universal Thermal Climate Index (UTCI) based on the most
advanced multi-node model of thermoregulation representing progress in science within the last three to four decades, both
in thermo-physiological and heat exchange theory. Creating the essential research synergies for the development of UTCI required
pooling the resources of multidisciplinary experts in the fields of thermal physiology, mathematical modelling, occupational
medicine, meteorological data handling (in particular radiation modelling) and application development in a network. It was
possible to extend the expertise of ISB Commission 6 substantially by COST (a European programme promoting Cooperation in
Science and Technology) Action 730 so that finally over 45 scientists from 23 countries (Australia, Canada, Israel, several
Europe countries, New Zealand, and the United States) worked together. The work was performed under the umbrella of the WMO
Commission on Climatology (CCl). After extensive evaluations, Fiala’s multi-node human physiology and thermal comfort model
(FPC) was adopted for this study. The model was validated extensively, applying as yet unused data from other research groups,
and extended for the purposes of the project. This model was coupled with a state-of-the-art clothing model taking into consideration
behavioural adaptation of clothing insulation by the general urban population in response to actual environmental temperature.
UTCI was then derived conceptually as an equivalent temperature (ET). Thus, for any combination of air temperature, wind,
radiation, and humidity (stress), UTCI is defined as the isothermal air temperature of the reference condition that would
elicit the same dynamic response (strain) of the physiological model. As UTCI is based on contemporary science its use will
standardise applications in the major fields of human biometeorology, thus making research results comparable and physiologically
relevant. 相似文献
7.
McLellan TM 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2001,128(4):691-700
When protective clothing is worn that restricts evaporative heat loss, it is not valid to assume that the higher sweat rates associated with improvements in aerobic fitness will increase heat tolerance. An initial study compared thermoregulatory and cardiovascular responses to both compensable and uncompensable heat stress before and after 8 weeks of endurance training in previously sedentary males. Despite a 15% improvement in VO2peak, and lower heart rates and rectal temperature (T(re)) responses while wearing combat clothing, no changes were noted when subjects wore a protective clothing ensemble. Tolerance times were unchanged at approximately 50 min. A subsequent short-term training model that used daily 1-h exercise sessions for 2 weeks also failed to show any benefit when the protective clothing was worn in the heat. Cross-sectional comparisons between groups of high and low aerobic fitness, however, have revealed that a high aerobic fitness is associated with extended tolerance time when the protective clothing is worn. The longer tolerance time is a function of both a lower starting T(re) and a higher T(re) tolerated at exhaustion. Improvements in cardiovascular function with long-term training may allow higher core temperatures to be reached prior to exhaustion. Conversely, elevations in core temperature that occur with normal training sessions may familiarize the more fit subjects to the discomforts of exercise in the heat. Other factors such as differences in body fatness may account for a faster increase in tissue temperature at a given metabolic rate for less fit individuals. 相似文献
8.
This paper reports on a new transient thermal model integrating the heat and moisture transfer through clothing as well as the two-node human physiological model to predict the human physiological responses. For the first time, the model considered clothing ventilation and moisture accumulation on the surface of the skin and inner surface of the underwear. The numerical results of the model agreed well with a set of published experimental data and another set of experimental data from our own experiments. 相似文献
9.
S. E. Tuller 《International journal of biometeorology》1980,24(1):97-106
The human thermal bioclimatic effects of urbanization and natural topographic features (the ocean and hills) were investigated during clear winter nights in Christchurch, New Zealand. Results are presented in terms of the amount of clothing insulation required to balance the body heat budget equation of a standing person with no change in body heat storage. The ordering of urban-rural land use zones from lowest to highest clothing requirements was: CBD, light industrial-commercial, residential and rural. Air temperature accounted for most of the variation in clothing requirement with the model used and weather conditions investigated here followed by environmental thermal radiation. The oceans and hill slopes had an effect comparable to that of most of the urban area and required less clothing than did all land use zones except the urban CBD. 相似文献
10.
Based on results from a field survey campaign conducted in Switzerand, we show that occupants’ variations in clothing choices,
which are relatively unconstrained, are best described by the daily mean outdoor temperature and that major clothing adjustments
occur rarely during the day. We then develop an ordinal logistic model of the probability distribution of discretised clothing
levels, which results in a concise and informative expression of occupants’ clothing choices. Results from both cross-validation
and independent verification suggest that this model formulation may be used with confidence. Furthermore, the form of the
model is readily generalisable, given the requisite calibration data, to environments where dress codes are more specific.
We also observe that, for these building occupants, the prevailing metabolic activity levels are mostly constant for the whole
range of surveyed environmental conditions, as their activities are relatively constrained by the tasks in hand. Occupants
may compensate for this constraint, however, through the consumption of cold and hot drinks, with corresponding impacts on
metabolic heat production. Indeed, cold drink consumption was found to be highly correlated with indoor thermal conditions,
whilst hot drink consumption is best described by a seasonal variable. These variables can be used for predictive purposes
using binary logistic models. 相似文献
11.
Many documented studies have demonstrated the human mortality rate increases during severe heatwaves. There remains a need for further explore ecologically valid cooling strategies to alleviate body heat strain during extreme heatwaves. The main aim of this work was to explore whether intermittent wetting clothing can be served as an ecologically valid cooling strategy to mitigate heat stress on inactive vulnerable populations not having access to air-conditioning during a severe heatwave. Ten young male subjects underwent two 90-min separate trials: a dry clothing trial (i.e., CON) and a wetted clothing cooling trial (i.e., WEC). A set of light summer wear was chosen and intermittently wetted by tap water at intervals of every 30 min. Physiological and perceptual responses of subjects were examined and compared. All trials were performed in a chamber with an air temperature of 43 ± 0.5 °C, RH= 57 ± 5% and an air velocity of 0.15 ± 0.05 m/s (WBGT=37.35 °C). Results demonstrated that WEC, compared with CON, could significantly reduce both the mean skin temperature and the core temperature throughout the 5–90th min and 25–90th min of the trial, respectively (p < 0.05). Besides, WEC could also remarkable reduce local skin temperatures at those body sites covered by wet clothing (p < 0.05). In comparison, no significant difference was found between WEC and CON on perceptual responses. Further, it was also found from PHS simulations that conditions with a partial water vapour pressure ≤ 3.1–3.5 kPa would not induce pronounced core temperature rises at 43 °C. Finally, it may be concluded that intermittent wetting clothing could be served as an ecologically valid cooling strategy to reduce thermophysiological strain of vulnerable populations while seating during humid heatwaves and thereby improve their health and safety. 相似文献
12.
The physiological equivalent temperature – a universal index for the biometeorological assessment of the thermal environment 总被引:8,自引:0,他引:8
P. Höppe 《International journal of biometeorology》1999,43(2):71-75
With considerably increased coverage of weather information in the news media in recent years in many countries, there is
also more demand for data that are applicable and useful for everyday life. Both the perception of the thermal component of
weather as well as the appropriate clothing for thermal comfort result from the integral effects of all meteorological parameters
relevant for heat exchange between the body and its environment. Regulatory physiological processes can affect the relative
importance of meteorological parameters, e.g. wind velocity becomes more important when the body is sweating. In order to
take into account all these factors, it is necessary to use a heat-balance model of the human body. The physiological equivalent
temperature (PET) is based on the Munich Energy-balance Model for Individuals (MEMI), which models the thermal conditions
of the human body in a physiologically relevant way. PET is defined as the air temperature at which, in a typical indoor setting
(without wind and solar radiation), the heat budget of the human body is balanced with the same core and skin temperature
as under the complex outdoor conditions to be assessed. This way PET enables a layperson to compare the integral effects of
complex thermal conditions outside with his or her own experience indoors. On hot summer days, for example, with direct solar
irradiation the PET value may be more than 20 K higher than the air temperature, on a windy day in winter up to 15 K lower.
Received: 14 December 1998 / Accepted: 26 May 1999 相似文献
13.
Peter Tikuisis 《European journal of applied physiology and occupational physiology》1989,59(5):334-341
A multi-compartmental thermoregulatory model was applied to data of ten resting clothed males immersed for 3 h in water at 10 and 15 degrees C. Clothing consisted of a dry suit and either a light or heavy undergarment, representing a total insulation of 0.15 (0.95) or 0.20 m2 degrees CW-1 (1.28 clo), respectively. Data were grouped according to low (less than 14%) and high (14 to 24%) body fat individuals. Mean decreases in rectal temperature ranged from 0.79 to 1.38 degrees C, mean decreases in the mean weighted skin temperature ranged from 6.3 to 10.2 degrees C, and mean increases in the metabolic rate ranged from 33.9 to 80.8 W. The model consists of eight segments, each representing a specific region of the body. Each segment is comprised of compartments representing the core, muscle, fat, skin, and clothing. Each compartment is assigned thermophysical values of heat conduction and heat capacitance, and with the exception of clothing, physiological values of blood flow and metabolic heat production. During cold exposure, responses are directed towards increased heat production in the form of shivering and heat conservation in the form of vasoconstriction and convective heat exchange at the vascular level. Agreement between the model predictions and the experimental observations was obtained by adjusting the parameters governing these responses.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
14.
《Journal of thermal biology》2006,31(6):461-466
1. The thermal parameters for describing clothing were summarized first (i.e., clo and tog unit, permeability index, evaporative transmissibility, permeation efficiency factor, index of water permeability). Their applications were then outlined for the calculation of heat exchange between human body and its environment, and for the prediction of the physiological variables under heat stress conditions.2. Nevertheless, the human body is not frequently exposed under steady-state condition, instead it is subjected to changes in environmental variables, clothing and activity. The transient thermal response of the human-clothing system plays a major role during transients. The heat exchange between the body and the environment may be affected significantly by the dynamic response of the clothing. The thermal comfort property of a clothing system during dynamic conditions should be assessed based on moisture vapor pressure alteration within the clothing, surface temperature of the clothing and heat loss from the body.3. There is a trend to develop overall thermal parameter to describe the transient thermal and moisture transfer properties of clothing system. 相似文献
15.
Marco Morabito Daniela Z. Pavlinic Alfonso Crisci Valerio Capecchi Simone Orlandini Igor B. Mekjavic 《International journal of biometeorology》2011,55(4):481-490
Military and civil defense personnel are often involved in complex activities in a variety of outdoor environments. The choice
of appropriate clothing ensembles represents an important strategy to establish the success of a military mission. The main
aim of this study was to compare the known clothing insulation of the garment ensembles worn by soldiers during two winter
outdoor field trials (hike and guard duty) with the estimated optimal clothing thermal insulations recommended to maintain
thermoneutrality, assessed by using two different biometeorological procedures. The overall aim was to assess the applicability
of such biometeorological procedures to weather forecast systems, thereby developing a comprehensive biometeorological tool
for military operational forecast purposes. Military trials were carried out during winter 2006 in Pokljuka (Slovenia) by
Slovene Armed Forces personnel. Gastrointestinal temperature, heart rate and environmental parameters were measured with portable
data acquisition systems. The thermal characteristics of the clothing ensembles worn by the soldiers, namely thermal resistance,
were determined with a sweating thermal manikin. Results showed that the clothing ensemble worn by the military was appropriate
during guard duty but generally inappropriate during the hike. A general under-estimation of the biometeorological forecast
model in predicting the optimal clothing insulation value was observed and an additional post-processing calibration might
further improve forecast accuracy. This study represents the first step in the development of a comprehensive personalized
biometeorological forecast system aimed at improving recommendations regarding the optimal thermal insulation of military
garment ensembles for winter activities. 相似文献
16.
Effects of wearing two different forms of garment on thermoregulation in men resting at 10 degrees C
W S Jeong H Tokura 《European journal of applied physiology and occupational physiology》1988,57(5):627-631
We have compared the human thermoregulatory responses and clothing microclimate temperature when the body core-shell ratio was changed by wearing two different forms of garment. Each was worn for 160 min at an ambient temperature of 10 degrees C and a relative humidity of 50% by six healthy males in the supine posture. One garment covered the whole body area except for the face (long-sleeves: L-S), the other covered the central body area alone (half-sleeves: H-S). Major findings are summarized as follows: 1) Rectal temperature was kept higher by H-S than L-S even though L-S showed higher thermal resistance values. 2) The standard deviation of rectal temperature was smaller in H-S. 3) Trunk skin and clothing microclimate temperatures were also kept higher by H-S. We suggest that the reduced level of rectal temperature in L-S might be ascribed to a different pattern of venous return originating in the mechanisms of the counter-current heat exchange system: the venous return from the periphery into the thoracic and abdominal areas being cooler in L-S than in H-S. 相似文献
17.
Clothing evaporative resistance is an important input in thermal comfort models. Thermal manikin tests give the most accurate and reliable evaporative resistance values for clothing. The calculation methods of clothing evaporative resistance require the sweating skin surface temperature (i.e., options 1 and 2). However, prevailing calculation methods of clothing evaporative resistance (i.e., options 3 and 4) are based on the controlled nude manikin surface temperature due to the sensory measurement difficulty. In order to overcome the difficulty of attaching temperature sensors to the wet skin surface and to enhance the calculation accuracy on evaporative resistance, we conducted an intensive skin study on a thermal manikin ‘Tore’. The relationship among the nude manikin surface temperature, the total heat loss and the wet skin surface temperature in three ambient conditions was investigated. A universal empirical equation to predict the wet skin surface temperature of a sweating thermal manikin was developed and validated on the manikin dressed in six different clothing ensembles. The skin surface temperature prediction equation in an ambient temperature range between 25.0 and 34.0 °C is Tsk=34.0–0.0132HL. It is demonstrated that the universal empirical equation is a good alternative to predicting the wet skin surface temperature and facilitates calculating the evaporative resistance of permeable clothing ensembles. Further studies on the validation of the empirical equation on different thermal manikins are needed however. 相似文献
18.
Estimating outdoor thermal comfort using a cylindrical radiation thermometer and an energy budget model 总被引:2,自引:2,他引:0
A mathematical model to estimate outdoor thermal comfort for humans from micrometeorological data has been formulated using the energy balance concept and the simultaneous satisfaction of four criteria for comfort from the literature: (a) a comfortable perspiration rate, (b) a comfortable core body temperature, (c) a comfortable skin temperature, and (d) a near-zero energy budget. A cylindrical modification of the globe thermometer is proposed as a simple monitor of outdoor radiation absorption for a person, and the effect of windspeed on the thermal resistance of clothing is considered. Results show a correlation coefficient of 0.91 between model output and subjective comfort ratings of 59 different situations with a variety of temperatures, insolations and windspeeds. 相似文献
19.
D C Gavhed R Nielsen I Holmér 《European journal of applied physiology and occupational physiology》1991,63(1):29-35
Thermoregulatory and thermal subjective responses were studied in ten male, clothed subjects during continuous (C) and intermittent (I) exercise at the same average level of oxygen consumption. The subjects performed both I and C twice, dressed in two different three-layer cold-protective clothing ensembles of two thermal insulation levels [total clothing insulation = 2.59 clo (L) and 3.20 clo (H)]. Experiments were carried out at an ambient temperature of -10 degrees C. Rectal temperatures increased similarly in both types of exercise. Mean skin temperature (Tsk) was lower in I compared to C with both levels of clothing insulation. Over the last 0.5 h of the experiment Tsk was approximately 1.3 degrees C lower in I than in C for clothing L. The skin evaporation rate was higher in clothing H than L but did not differ between I and C. Subjective ratings for thermal sensations of the whole body (BTS) and hands were close to neutral in I and around slightly warm in C. The BTS was lower in I than in C and was lower in L compared to H. It was concluded that, at equal average energy expenditure, thermal responses to intermittent and continuous exercise in the cold differ in clothed subjects, principally as a result of different patterns of heat exchange. 相似文献
20.
Predicting urban outdoor thermal comfort by the Universal Thermal Climate Index UTCI—a case study in Southern Brazil 总被引:1,自引:0,他引:1
Recognising that modifications to the physical attributes of urban space are able to promote improved thermal outdoor conditions
and thus positively influence the use of open spaces, a survey to define optimal thermal comfort ranges for passers-by in
pedestrian streets was conducted in Curitiba, Brazil. We applied general additive models to study the impact of temperature,
humidity, and wind, as well as long-wave and short-wave radiant heat fluxes as summarised by the recently developed Universal
Thermal Climate Index (UTCI) on the choice of clothing insulation by fitting LOESS smoothers to observations from 944 males
and 710 females aged from 13 to 91 years. We further analysed votes of thermal sensation compared to predictions of UTCI.
The results showed that females chose less insulating clothing in warm conditions compared to males and that observed values
of clothing insulation depended on temperature, but also on season and potentially on solar radiation. The overall pattern
of clothing choice was well reflected by UTCI, which also provided for good predictions of thermal sensation votes depending
on the meteorological conditions. Analysing subgroups indicated that the goodness-of-fit of the UTCI was independent of gender
and age, and with only limited influence of season and body composition as assessed by body mass index. This suggests that
UTCI can serve as a suitable planning tool for urban thermal comfort in sub-tropical regions. 相似文献