Estimation of thermal sensation using PMV and SET under high air movement conditions

1. 1. Our previous experimental results showed the thermal sensation vote was much less than the values of PMV and SET^* at air velocities above 0.5 m/s.

2. 2. The method to modify SET^* is presented from the results of subjective experiments taking account of decrease in clo value of summer clothing and decrease in skin wettedness due to increased air velocity.

3. 3. Thermal resistance under increased air movement on a standard summer clothing ensemble was measured. Basic thermal insulation of the summer ensemble was reduced by 25% at air velocity of 1.0 m/s.

4. 4. Thirty-two subjects were exposed at operative temperatures of 27 and 30°C under 1 m/s air movement in order to determine the amount of skin diffusion. Measured evaporation heat loss from skin surface was much smaller at air velocity of 1 m/s than that predicted by SET^*.

5. 5. Estimated thermal sensation vote using modified SET^* agreed well with our previous experimental results under different air velocities for the same clothing.

Man in extreme thermal environment—predictions based on a PC-model

1. 1. A mathematical model of human temperature regulation written in MS-FORTRAN for personal computer treatment is now available enabling the prediction of radial temperature profiles, of metabolic heat production, of blood flow and of sweat production in six body compartments for a broad spectrum of environmental conditions.

2. 2. The computed results show a good compatibility with experimental results and may be used for prediction of extreme situations for which experimental data are not available.

A study on body temperature regulation and residential thermal environments of the elderly—I. whole country survey of residential thermal environment and evaluation methods: RTE-index

1. 1. As part of “research on environmental comfort,” that is, research which aims to make people's living environment more comfortable, we attempted to clarify the relation between the living environment of elderly people and physiological and psychological factors. We carried out a comprehensive study with a view to establishing comfort standards for the residential thermal environment, and for creating evaluation and control systems.

2. 2. The comfort of the living environment is closely related to the thermal environment and the temperature-regulation ability of the human body. This ability of the body to regulate temperature develops during childhood and recedes as the adult ages.

3. 3. We therefore carried out: (a) experiments on body-temperature regulation and on special characteristics of the body-temperature regulation of elderly people, (b) a nationwide survey of the actual residential thermal environments of elderly people and (c) a survey of the daily activities of elderly people, and how elderly people's physiological and psychological conditions change when they are engaged in these activities.

4. 4. As a result of these experiments and surveys, we were able to: (d) formulate standards for evaluation of the residential thermal environment and (e) numerically express the results of systematic evaluation of residential thermal environments of elderly people, by means of a RTE-index.

SCENARIO revisited: comparisons of operational and rational models in predicting human responses to the environment

1. This paper focuses on thermoregulatory modeling of individual variability in environmental extremes.

2. A great many worthwhile models do a reliable job describing the heat balance equation using a first principles approach by fitting operational equations or by using multi-node thermoregulatory servo-control models.

3. A soldier-based physiological/thermoregulatory model (SCENARIO (J. Therm. Biol. 22 (1997) 331) was enhanced using a probabilistic application of the Bayesian statistical paradigms in conjunction with Monte Carlo methods (SCENARIO-MC).

4. Coefficients improving the model include: algorithms for circadian and menstrual cycle offsets on the hypothalamic controller and an output depiction of correlation matrices between specific environmental and physiologic variables.

5. The model was found to be robust (based on root mean square deviations ) particularly in physiological strain index prediction and able to predict individual esophageal and heart rate responses in women exposed to upward and downward thermal transients and wide perturbations of work/rest exercise in the heat while wearing protective clothing.

Characteristics of wettedness under constant average skin temperature

1. 1. Experiments were carried out concerning the characteristics of wettedness revealed under constant average skin temperature using sitting-resting nude subjects. From the basic measurements of both environmental parameters and human physiological responses, the conclusions detailed below were proposed regarding the changes of wettedness under constant average skin temperature.

2. 2. There is positive correlation between the wettedness and environmental humidity, and negative correlation between the wettedness and air temperature.

3. 3. There is positive correlation between the evaporative heat loss from the skin surface and air temperature, and negative correlation between the evaporative heat loss and environmental humidity.

4. 4. There is negative correlation between the wettedness and evaporative heat loss.

5. 5. Wettedness is not constant but takes varying values, that is, corresponding to each average skin temperature both the maximum and the minimum wettedness values occur.

6. 6. Deriving from the items mentioned above, the theoretical locus of equal average skin temperature is not a straight line, but is a curved line plotted on the psychrometric chart.

Environmental stress after atropine treatment

1. 1.|Atropine administration resulted in higher skin temperatures in both sensible and insensible environments and a higher core temperature in the hot environment, due to the reduction in whole body sweating. Exercise time was reduced 28 min following atropine in the hot environment, but was not affected in the humid environment.

2. 2.|The effect of heat storage (significantly higher after atropine) was shown to be greater in the hot environment due to inadequate sweat secretion for subsequent evaporative cooling. In the warm environment, enhanced sensible heat loss resulted in more effective thermoregulation.

3. 3.|Based on the effective temperature (ET^*) it is suggested that exercise in the heat can be accomplished during environmental stress at warm temperatures after atropine treatment.

Indoor environmental study and post occupancy evaluation in an office environment

1. 1. The objective of this paper is to investigate the indoor environment from the viewpoint of interaction between physical environment and the human responses. The field survey has been conducted over 1 year.

2. 2. A continuous measurement has been carried out for 1 week and distribution of variables have been measured for 1 day.

3. 3. The attitude of workers was investigated by a questionnaire.

4. 4. As the result, average luminance represented more than 1000 lx in the new building, in contrast with less tha 300 lx in the existing building.

5. 5. There was a significant difference of the occupants' response to the light environment between the two buildings.

6. 6. Measured thermal conditions are on the edge of the ASHRAE comfort envelope in summer, and in the neighborhood of the lower dry limit of the envelope in spring.

7. 7. The occupants' evaluations were remarkably changed before and after the moving. The office environment is better than that of the factory.

A study on thermal environment for physically handicapped persons. Results from Japanese-Hungarian joint experiment in 1990

1. 1. For the scientific evaluation of thermal environment in relatin to human health and comfort, a number of indices have been proposed in the recent 70 years.

2. 2. However, even the newest indices are still not sufficient to explain the general thermal environment for all people including infants, the aged, the disabled etc., because such indices are based more or less on experiments using college age persons.

3. 3. Series of studies to find required thermal conditions for the disabled and the aged have been carried out from 1976 in Japan and from 1988 in Hungary.

4. 4. In 1990, the Japanese and Hungarian research groups have collaborated in an international joint experiment on the thermal environment for the disabled.

5. 5. This paper reports on the results from the first step examinations of the data from above mentioned joint experiment.

Effect of environmental temperature on biosynthesis of liver phosphatidyl-choline in the trout (Salmo gairdnerii)

1. 1.The changes in fatty acid composition of trout liver phosphatidyl-choline, when the environmental temperature was increased, resulted in modifications in the amounts of the different molecular species.

2. 2.In vivo, incorporation of ³²P occurred more rapidly in the molecular species with high degree of unsaturation.Temperature acclimation did not modify the relative proportions of label shown in the five subfractions.

3. 3.In vitro incorporation of ¹⁴C-methyl-choline also occurred more rapidly in the most unsaturated molecular species. However, when the incubation temperature was raised, the proportion of label decreased in the unsaturated fractions.

Ethanol effects on temperature-sensitive hypothalamic neurons in rat brain slices

1. We recorded impulse activity of thermosensitive hypothalamic neurons in rat brain slices during superfusion with ethanol at constant temperatures and during slow sinusoidal temperature changes.

2. At constant temperatures of 37 °C, ethanol application typically induced a triphasic change of the firing rate: An initial excitation turned into complete inhibition followed by spontaneous recovery to higher firing rates.

3. Ethanol application increased the neurons’ temperature sensitivity remarkably.

4. Our data indicate complex neuromodulatory effects of ethanol with different time delays which interfere with basic mechanisms of temperature transduction.

Thermal resistance of the ciliary activity in the gills of the fresh water mussel Anodonta anatina

1. 1.|The thermal resistance of the activity of frontal cilia in the median gills of the fresh water mussel Anodonta anatina was studied.

2. 2.|The resistance acclimation appeared in 2 days in the gills of intact animals, but not in the isolated gills kept at 4, 14 and 24°C, for between 1 to 3 days.

3. 3.|Warm-acclimation increased the ACh sensitivity of the gills of intact mussels.

4. 4.|Isolation of the gills enhanced the thermal resistance.

5. 5.|ACh, choline and tetramethylammonium enhanced the thermal resistance in the isolated gills. whereas atropine and physostigmine diminished it.

6. 6.|It is concluded that in A. anatina the control if the thermal resistance is probably neural.

The effects of wind and thermal radiation on thermal responses during rest and exercise in a cold environment

1. 1. The purpose of this study was to investigate the effects of thermal radiation and wind on thermal responses at rest and during exercise in a cold environment.

2. 2. The experimental conditions were radiation and wind (R + W), no radiation and wind (W), radiation and no wind (R), no radiation and no wind (C).

3. 3. The air temperature was −5°C. Thermal radiation was 360 W/m². Air velocities were 0.76, 1.73 and 2.8 m/s. Rectal and skin temperatures, heart rate and oxygen consumption were recorded. Thermal and comfort sensations were questioned.

4. 4. There are no significant effects of thermal radiation and wind on the physiological responses except the mean skin temperature. There are significant effects on the mean skin temperature (P < 0.01) and thermal sensation (P < 0.05).

Discrimination of thermal sensation in unhomogeneous thermal environments using theory of quantification II

1. 1. One hundred and forty-five thermal-sensation tests by subjects were performed in unhomogeneous thermal environments and the whole body and the lower leg thermal-sensations were discriminated with physical data of the thermal environments using the discrimination analysis and the expanded theory of quantification II which is able to deal with data including quantitative continuous-variables and qualitative category-variables simultaneously.

2. 2. The discrimination of the whole-body thermal-sensations on the basis of the local-body thermal sensations was also done.

3. 3. As a result, it is shown that the discrimination analysis and the expanded theory of quantification II are able to discriminate the thermal sensation in unhomogeneous environments.

Transient response of the human-clothing system

1. 1. A transient clothing model which considers the effects of adsorption and thermal capacitance on the dynamic thermal response of clothing was developed.

2. 2. Moisture adsorption and desorption by the fabric are the major factors that affect the transient response of clothing.

3. 3. This moisture can come from evaporated sweat or from the environment.

4. 4. The clothing model was combined with a modified version of the two-node thermal model of the human body.

5. 5. The combined model shows that, during transients, the mix of latent and sensible heat flow from the skin may differ considerably from the corresponding heat flows from the clothing surface to the environment.

6. 6. The alteration of the heat flows can have a significant impact on the thermal response of the body by changing the sweat rate required to achieve the heat loss necessary to maintain thermal balance.

Thermosensitivity of the preoptic region and the spinal cord in the golden hamster

1. 1.|The effects of thermal stimulation of the preoptic region (POAH) and the spinal cord on non-shivering thermogenesis (NST) and shivering were studied in euthermic golden hamsters.

2. 2.|Shivering intensity is suppressed by heating the POAH but is independent of spinal cord temperature. Therefore, NST in the interscapular brown adipose tissue does not suppress shivering.

3. 3.|NST is inhibited by heating of the POAH as well as of spinal cord. It is discussed that the control of NST by two different central thermosensitive areas is significant for thermoregulation during exercise.

A theory of evaluation applied to human-environment systems

1. 1. The writers present the general theory of evaluation that is being developed by their group.

2. 2. The evaluation of a human environment is a complex mental process.

3. 3. In an effort to express numerically the quality of an environment, one tends to oversimplify the complex aspects of it and the entailing problems in relation to its inhabitants.

4. 4. In this paper, some examples are taken in the evaluation of thermal environments, wherein much has been said and done in setting up numerical scales to express human comfort, and yet neither clear-cut explanations nor convincing logic seem to exist to terminate the argument over the widely scattered and sometimes seemingly contradicting experimental data.

5. 5. The writers suggest that many of the reasons for this confusion may be traced back to the oversimplified notion of evaluation.

6. 6. It is shown that there are various possibilities when looking at the scales of evaluation.

7. 7.|The nominal scale, least studied of all the four traditional scales, may be given a prominent place in evaluating a thermal environment. The pseudo-interval order scale is another example.

Thermal acclimation, hydroperoxide detoxifying enzymes and oxidative stress in the lung and liver of Rana perezi

1. 1.Rana perezi adult frogs were acclimated to cold (10 ± 2°C) and warm (29 ± 1°C) temperatures for 4 months.

2. 2.After acclimation, a partial compensation of the oxygen consumption of the animals was found because of a reduction of its thermal sensitivity.

3. 3.Activities of liver and lung catalase, selenium (Se)-dependent and Se-independent glutathione peroxidases were not changed by thermal acclimation.

4. 4.Tissue peroxidation (TBA-RS) increased in the liver of heat acclimated animals.

5. 5.Hydroperoxide detoxifying enzyme activities did not show inverse compensation of temperature during acclimation. It is proposed that the pattern of thermal compensation shown by these enzymes in different species depends on a variety of factors including: (a) the thermal sensitivities of hydroperoxide producing and scavenging systems; (b) the changes induced by acclimation in the rate of hydroperoxide generation.

Skin temperatures, thermosensory and pleasantness estimates in case of heterogeneity in the thermal environment

1. 1. Seven thermal conditions were imposed on male sitting subjects (slightly clothed: 0.6 clo).

2. 2. A thermal mannikin was also used to determine the exact operative temperature, T₀.

3. 3. Conditions were: uniform (UN: all parameters at 24.5°C, air velocity at 0.15 ms⁻¹), heated ceiling (HC at 45°C), heated floor (HF at 34°C), cold floor (CF at 14°C), two conditions of one cold wall at 6°C (CW1 and CW2 respectively with and without air temperature compensation) and increased air velocity (AV at 0.4 ms⁻¹).

4. 4. Local skin temperatures and answers to questionnaires were obtained.

5. 5. Skin temperature variations were affected by conditions and slight T₀ changes.

6. 6. Comfort judgments were fairly well related to T₀, especially when expressed as differences between actual non-uniform environment and the uniform one.

7. 7. It is concluded that, in case of non-uniform environments close to thermoneutral zone, thermal comfort or discomfort reflects the climate alterations better than the thermal sensation does.

The effect of 4-methyl-histamine on temperature regulation in the rat

1. 1. The histamine H₂-antagonist, 4-methyl-histamine causes a fall in body temperature when injected into the third ventricle of the rat.

2. 2. The hypothermia is prevented by prior intraventricular injection of an H₂-antagonist, metiamide, but not by an H₁-antagonist, pyrilamine.

3. 3. The fall in temperature is accompanied by increased cutaneous heat loss.

4. 4. These data support the concept that there are H₂-receptors in the central thermoregulatory pathways of the rat.