Thermal Perception Research Articles

Thermal perception of non-uniform and dynamic air-conditioned environment in the elderly

Due to the decline of the elderly's thermophysiology, the elderly is more sensitive to changes in airflow. Traditional thermal sensation equation was a steady-state model only based on the average of surrounding thermal environment parameters, which cannot describe the thermal perception to the spatial uniformity and temporal fluctuation of the parameters. To characterize the thermal perception of non-uniform and dynamic air-conditioned environments in the elderly, this study determined the characteristics of thermal environment at twenty-four monitoring points (three heights and eight directions) around the elderly through laboratory test. Seven elderly participated in the experiment and were asked to fill in the questionnaire to obtain thermal perception. Different typical airflow with 26 °C set temperature of air-conditioner were set as the measuring conditions. Uniformity and fluctuation indexes were proposed to qualify the spatial and temporal distribution. The results showed that the average of the parameters was basically in the acceptable comfort zone. Through establishing the thermal sensation model based on the average, uniformity, and fluctuation indexes, thermal sensations were only significantly affected by fluctuation of temperature, velocity uniformity, turbulence, and average relative humidity. Compared to traditional model, established model can not only depict the elderly's strong perception of temperature change by temperature fluctuation index, but also refine the elderly's relatively weak perception of static average velocity into a strong perception of the velocity uniformity and turbulence. The R square of this model was 0.153 greater than that of traditional model.

Thermal responses in temporarily occupied space in the summer: Spatial-temporal synergetic alliesthesia using a ceiling fan

Although temporal and spatial alliesthesia have been widely studied in recent decades, their synergistic impact on occupant perceptions have received less attention. One reason for this is that prior to the concept of temporarily occupied space (TOS), real-world application circumstances were not clearly defined. TOS were defined as air-conditioned indoor facilities where the majority of people spend shorter than a set time period, such as banks, fast-food restaurants and train station waiting spaces (about 40 min). In this study, thermal responses based on the spatial-temporal synergetic alliesthesia were investigated. According to the association of human physiological parameters with thermal perception responses, a thermal sensation model was developed. Reasonable indoor design temperatures to achieve energy-efficient comfort were determined. Chamber tests were performed on acclimatized human volunteers to determine spatial-temporal synergetic alliesthesia. Besides, an actual building was used for transient energy consumption simulations. For this study, a TOS with a non-adjustable ceiling fan (0.85 m/s, 128 rpm, 17.2 W) setting was used. The results showed that 27 °C and 55%RH are the best HVAC control target settings for the air-conditioned TOS with ceiling fans. It has the potential to save 34% of energy (26.8 kWh/m2·yr) while maintaining the thermal comfort of the human body. The high-accuracy thermal sensation model for spatial-temporal synergetic alliesthesia demonstrated good agreement with experimental data that were not used in the regression development. TOS can be used as a real-world example of the spatial-temporal synergetic alliesthesia. The findings of this study are useful for promoting and applying alliesthesia in the field of buildings, as well as for energy-saving thermal comfort.

485-P: Proteomic Analysis Reveals Different Therapeutic Mechanisms for Diabetic Neuropathy between DPP-4 Inhibitor and SGLT2 Inhibitor

Aim: Diabetic neuropathy (DN) is the most prevalent complication with microangiopathy in diabetes. Although, DN would decrease quality of life, currently there is no radical treatment for DN. DPP-4 inhibitor (DP4i) and SGLT-2 inhibitor (SG2i) have been experimentally shown to possibly ameliorate DN. However, the difference in the mechanism between two agents has not been clarified so far. In this study, we performed proteomic analysis of the sciatic nerve (SN) and dorsal root ganglion (DRG) of Goto-Kakizaki rats (GK), a model of lean type 2 diabetes, treated with DP4i and/or SG2i. Methods: Male GK and control Wister rats (W) were used. Since 5 weeks of age, GK rats were treated with 10mg/day DP4i (Te), 10mg/ day SG2i (Ca), and DP4i + SG2i (CaTe) until 29 weeks of age. Thermal perception was evaluated by tail flick test. At the end of experiment, SN, DRG, and skin tissue were dissected. Proteomic analysis was performed with SN and DRG tissues by mass spectrometry. In the skin, fluorescent immunostaining with anti-PGP 9.5 antibody was performed for the assessment of intraepidermal nerve density (IENFD). Results: Tail flick test and IENFD were significantly decreased in GK compared to W (p<0.05), and significantly improved in Te, Ca, and CaTe (p<0.05, p<0.05 and p<0.01 vs GK, respectively). Proteomic analysis for SN showed only two pathways changed in Te, whereas seven and six pathways changed in the Ca and CaTe, respectively. Conversely, in the DRG, only two pathways changed in Ca, whereas the five and seven pathways changed in Te and CaTe, respectively. Conclusion: Our results suggest that the DP4i and SG2i act on the different sites of peripheral nervous system with different mechanism. Combining these two agents possibly have complementary effects on DPN treatment. Disclosure Y.Takeuchi: None. S.Osonoi: None. T.Sasaki: None. H.Mizukami: None. Funding Mitsubishi Tanabe Pharma Corporation

Single-cell transcriptomic profiling of dorsal root ganglion: an overview.

The somatosensory neurons in the dorsal root ganglion (DRG) are responsible to detect peripheral physical and noxious stimuli, and then transmit these inputs into the central nervous system. DRG neurons are composed of various subpopulations, which are suggested to respond to different stimuli, such as mechanical, thermal, and cold perception. For a long time, DRG neurons were classified based on anatomical criteria. Recently, single-cell (scRNA-seq) and single-nucleus RNA-sequencing (snRNA-seq) has advanced our understanding of the composition and functional heterogeneity of both human and rodent DRG neurons at single-cell resolution. In this review, we summarized the current literature regarding single-cell transcriptomic profiling of DRG to provide an integral understanding in the molecular transcriptomes, cell types, and functional annotations of DRG neurons in humans and rodents.

Effect of Prewarming on Postoperative Hypothermia, Vital Signs, and Thermal Comfort: A Randomized Controlled Trial.

This study aimed to determine the effects of preoperative active and passive warming on postoperative hypothermia, vital signs, and perception of thermal comfort in patients scheduled to undergo elective open abdominal surgery. This was a randomized controlled study. The study sample comprised 90 patients (30 in the active warming group, 30 in the passive warming group, and 30 in the control group) who agreed to participate and met the research criteria. According to the comparison of patients' vital signs, a statistically significant difference was observed in terms of patients' preoperative body temperature values (χ2 = 56.959; p = 0.000). A comparison of the patients' postoperative thermal comfort perception scores yielded a statistically significant difference (χ2 = 39.693; p = 0.000). Postoperative comfort scores in the active warming group were significantly higher than those in the passive warming and control groups. In conclusion, warming methods are effective in preventing undesirable postoperative hypothermia. The time to reach normothermia after surgery was shorter, vital signs were at a desirable level, and thermal comfort perceptions were higher in patients who were prewarmed. ClinicalTrials.gov (Identifier: NCT04997694).

Investigating the effects of climate on thermal adaptation: A comparative field study in naturally ventilated university classrooms

In educational buildings, adaptive strategies can be adopted for the achievement of thermal comfort and reduction of energy consumption. Since climate can largely affect thermal comfort, there is a need for understanding its role in the definition of different adaptive capacities, thermal neutrality, comfort, and preference.To this end, 17 naturally ventilated university classrooms from 10 different buildings located in two sub-climates of Italy (Mediterranean climate) and France (Continental climate) were analysed. In total, 1377 questionnaires associated with environmental parameters were collected. The same educational stage (i.e. university classrooms) and operation mode (i.e. naturally ventilated during the heating period) were investigated to remove possible biases related to their influence on thermal comfort perception.Field studies show that despite French students performing less adaptive actions, their neutral temperature (TN) was 3.1 °C lower than the Italian ones (TN,ITALY = 23.6 °C and TN,FRANCE = 20.5 °C) and this difference was statistically significant.Adaptation as a function of the sub-climate was evident from the comparison with the PMV-PPD model. Neutral temperatures calculated with PMV were higher than those obtained from TSV, and the difference increased for the French colder climate.Practically, students’ adaptation to colder environments can be deployed to ensure comfort while reducing the heating demand.

ID: 208242 Successful Treatment of Sjogren's Small Fiber Neuropathy With Dorsal Root Ganglion Stimulation

Small fiber neuropathy (SFN) is a chronic neuropathic pain disorder that is caused by damage to peripheral nerves, including small and myelinated (Aδ) and unmyelinated (C) fibers.1 Small, somatic, and autonomic fibers are responsible for regulation of thermal and pain perception, which control autonomic and enteric functions. Symptoms include allodynia, burning, hyperesthesia, paresthesia, numbness, abnormal sweating, and others.1

THERMAL COMFORT ASSESSMENT FOR ADOPTING CONTROL STRATEGIES IN ATRIUM BUILDINGS

The atrium was seen in origin about two hundred years ago. Glazed areas and atrium structures have been considered a symbol of advanced technology in recent years, yet they can differ in terms of arrangement and functionality. Because of the complexity of their operation and air movement, atriums are difficult to diagnose and analyze in terms of thermal comfort. The present paper has a study on the thermal environment of atrium spaces. Thermal comfort is one of the foremost important aspects of indoor environmental quality thanks to its effects on well-being, people's performance, and building energy requirements. Since our responses to our thermal environment have a considerable effect on our performance and behavior, not least in the realm of work, there has been a considerable scientific investigation of those responses and formal methods are developed for environmental evaluation and style. Thermal sensations of the occupants occupying the interior space of the building were evaluated with various approaches to understanding indoor thermal comfort. Several metrics for assessing human thermal response to interior environment conditions have been assessed describing the human thermal perception of the thermal environment to which an individual or a group of people is exposed. The article study was to gain insight into the subject’s perspectives on variables of comfort levels and determine the factors responsible for the varying human thermal comfort summer. This paper is a study on the thermal environment of atrium spaces focusing on identifying the factors of thermal comfort and promoting Control measures that may be adopted in atrium buildings to reduce the energy potential.

Topical application of isolated menthol and combined menthol-capsaicin creams: Exercise tolerance, thermal perception, pain, attentional focus and thermoregulation in the heat

ABSTRACT We determined the effects of topically applied (i) isolated menthol cream, (ii) menthol and capsaicin co-application or (iii) placebo cream on exercise tolerance, thermal perception, pain, attentional focus and thermoregulation during exercise in the heat. Ten participants cycled at 70% maximal power output until exhaustion in 35°C and 20% relative humidity after application of (i) 5% isolated menthol, (ii) 5% menthol and 0.025% capsaicin co-application or (iii) placebo cream. Thermo-physiological responses were measured during exercise, with attentional focus and pain determined post-exercise on a 0-to-10 scale. Across the three conditions, time to exhaustion was 13.4 ± 4.8 min, mean ± SD infrared tympanic and skin temperature was 37.2 ± 0.6°C and 35.1 ± 1.2°C, respectively, and heart rate was 152 ± 47 bpm, with no changes between conditions (p > 0.05). Perceived exertion was lower in the isolated menthol vs. all other conditions (p < 0.05, ηp2 = 0.44). Thermal sensation was higher in menthol-capsaicin co-application vs. isolated menthol (p < 0.05, d = 1.1), while sweat rate was higher for capsaicin and menthol co-application compared to menthol (p < 0.05, d = 0.85). The median and interquartile range scores for pain were lower (p < 0.05) in the menthol condition (8, 7-8) compared to both menthol and capsaicin (10, 9-10) and placebo (9, 9-10), which was coupled with a greater distraction (p < 0.05) in the menthol condition (9, 7-10) compared to placebo (6, 5-7). Despite no performance effects for any topical cream application condition, these data reiterate the advantageous perceptual and analgesic role of menthol application and demonstrate no advantage of co-application with capsaicin. Highlights Topical application of isolated menthol cream to cold-sensitive areas of the body during exhaustive exercise in the heat, elicited reduced perception of pain and enhanced sensation of cooling. While this reduction in generally unpleasant feelings (i.e. pain and heat) were coupled with lower RPE scores in the menthol condition and could be considered beneficial, there was no apparent ergogenic effect in an exercise tolerance test. Co-application of capsaicin and menthol appeared to inhibit the positive sensory effects elicited by menthol. Isolated menthol can induce changes in cognitive processes related to pain and exertion, while also reducing thermal sensation; however, the decision to use menthol creams must be balanced with the limited performance or thermoregulatory effects reported herein during exercise in hot environments.

Improvement of thermal perceptions and physiological responses using torso heating under short-term cold exposure

Short-term cold exposure (<1 h) may adversely affect human thermal comfort and health. Few studies have investigated the effectiveness of body heating in providing thermal protection to the torso against sharp temperature decreases, as well as the optimal operation modes of torso heating equipment. In this study, 12 male subjects were acclimatised in a room at 20 °C, then exposed to a cold environment at −2.2 °C, and finally returned to the room for recovery; each phase lasted 30 min. During cold exposure, they wore uniform clothing with an electrically heated vest (EHV) operated under these modes: no heating (NH), stage-regulated heating (SH), and intermittent alternating heating (IAH). Variations in subjective perceptions, physiological responses, and temperatures set for heating were recorded during the experiments. Torso heating mitigated the adverse effects of the large temperature down-step and continuous cold exposure on thermal perception and decreased the occurrence of three symptoms: cold hands or feet, running or stuffy noses, and shivering during cold exposure. After torso heating, the same skin temperature of the non-directly heated parts corresponded to a higher local thermal sensation, which was attributed to an indirect effect of the improved overall thermal state. The IAH mode could achieve thermal comfort at a reduced energy level, and it outperformed SH in subjective perception enhancement and self-reported symptom relief at lower heating temperatures. Additionally, under the same heating setting temperatures and power capacity, it could achieve an approximately 50 % longer usage time than SH could. The results suggest that intermittent heating protocol can be an efficient way to achieve thermal comfort and energy savings for personal heating devices.

Humid Heat Equally Impairs Maximal Exercise Performance in Elite Para-Athletes and Able-Bodied Athletes.

This study aimed to compare the impact of hot-humid environmental conditions on performance outcomes, thermoregulatory responses, and thermal perception during exercise between elite para- and able-bodied (AB) athletes. Twenty elite para-athletes (para-cycling and wheelchair tennis) and 20 elite AB athletes (road cycling, mountain biking, beach volleyball) performed an incremental exercise test in a temperate environment (mean ± SD, 15.2°C ± 1.2°C; relative humidity, 54% ± 7%) and a hot-humid environment (31.9°C ± 1.6°C, 72% ± 5%). Exercise tests started with a 20-min warm-up at 70% of maximal heart rate, after which power output increased by 5% every 3 min until volitional exhaustion. Time to exhaustion was shorter in hot-humid versus temperate conditions, with equal performance loss for para- and AB athletes (median (interquartile range), 26% (20%-31%) vs 27% (19%-32%); P = 0.80). AB athletes demonstrated larger exercise-induced increases in gastrointestinal temperature (T gi ) in hot-humid versus temperate conditions (2.2 ± 0.7 vs 1.7 ± 0.5, P < 0.001), whereas T gi responses in para-athletes were similar between conditions (1.3 ± 0.6 vs 1.3 ± 0.4, P = 0.74). Para- and AB athletes showed similar elevations in peak skin temperature ( P = 0.94), heart rate ( P = 0.67), and thermal sensation score ( P = 0.64) in hot-humid versus temperate conditions. Elite para-athletes and AB athletes demonstrated similar performance decrements during exercise in hot-humid versus temperate conditions, whereas T gi elevations were markedly lower in para-athletes. We observed large interindividual variation within both groups, suggesting that in both para- and AB athletes, personalized heat mitigation plans should be developed based on individual thermal testing.

Quantification of visual thermal perception changes in a wooden interior environment using physiological responses and immersive virtual environment

Wood can be used for various applications, such as for carbon storage, to enhance structural strength, and to promote biophilia; additionally, wooden building can positively affect the carbon footprint and well-being of occupants through changes in the thermal sensation by hue-heat hypothesis-based visual effects. However, previous studies focusing on the visual effect of indoor wood have limitations in terms of physical model implementation and subjective evaluation. In this study, an indoor wood application model is implemented using Virtual reality, and the subjective thermal sensation is quantitatively measured through physiological response measurement. The occupant's subjective thermal sensation is higher in the wood condition than in the nonwood condition and the occupant feels warmer as the level of wood application is increased. Physiological response, skin temperature, electrodermal activity, and electroencephalogram exhibit significant differences according to the level of wood application and similar tendencies to the data measured for the prediction of thermal sensation in previous studies. Using VR, the increase in the thermal sensation of occupants through the visual effect of wood without temperature control is confirmed through objective physiological parameters.

Evaluation of the Effects of Airflow Patterns on Human Thermal Perception

Recently, greenhouse gas emissions have led to irreversible climate change, and in order to mitigate the changes, more and more research is focusing on energy efficiency and environmental protection in the building sector. Improving indoor ventilation airflow as a feasible solution for energy conservation as well as improving human thermal comfort. This study aims to provide reference for optimizing the thermal perception of occupants in indoor ventilation design. This research evaluates the effect of heat perception on students in a stable indoor environment (28 ℃, RH 50%) under two airflow patterns (dynamic and constant). The use of airflow was found to have a positive impact on thermal sensation vote (TSV) and thermal pleasure vote (TPV). There was non-significant difference in the effects of heat perception between airflow modes. This finding is consistent with the findings of Parkinson and de Dear's study. It is worth noting that differences in experimental results may be due to other personal factors (e.g., gender, age, and weight). Further studies are therefore needed to demonstrate the influence of these factors on the thermal perception effect of air movement.

24-h movement behaviour, thermal perception, thirst, and heat management strategies of children and adults during heat alerts: a pilot study.

Background: Heat waves caused by climate change are increasingly challenging the wellbeing of individuals across the lifespan. Current efforts to understand the thermal perceptions and behaviours of people throughout the lifespan during heat waves are limited. Methods: Since June 2021, the Active Heatwave project has been recruiting households to better understand how individuals perceive, cope, and behave during heat waves. Using our novel web platform, participants were prompted to answer our Heat Alert Survey on days when a participants geolocation corresponded to a broadcasted local heat alert. Participants provided 24-h movement behaviour, thirst, thermal perception, and cooling strategies via validated questionnaires. Results: A total of 285 participants (118 children) from 60 distinct weather station locations globally participated between June and September 2021 and 2022. At least 1 heat alert (834 total) were identified from 95% (57/60) of the weather stations. Children reported spending more time performing vigorous intensity exercise compared to adults (p < 0.05), but no differences in thermal sensation, thermal comfort, or thirst sensation (all p > 0.31) were observed. For thirst management, 88% of respondents used water to relieve thirst, although notably, 15% of adults reported using alcohol. Regardless of age, staying indoors was the most common heat management strategy, whereas visiting cooling centres was the least. Conclusion: The present study presents a proof-of-concept combining local heat alert notifications with e-questionnaires for collecting near-real-time perceptual and behavioural data for both children and adults during heat waves. The observed patterns of behaviour suggest that present public heat-health guidelines are often ignored, children engage in fewer heat management strategies compared to adults, and these disparities highlight the need to improve public health communication and knowledge dissemination around promoting effective and accessible cooling solutions for children and adults.

Effects of phenylcapsaicin on aerobic capacity and physiological parameters in active young males: a randomized, triple-blinded, placebo-controlled, crossover trial.

Objective: Phenylcapsaicin (PC) is a new capsaicin analog which has exhibited a higher bioavailability. This sudy assessed the effects of a low dose (LD) of 0.625mg and a high dose (HD) of 2.5mg of PC on aerobic capacity, substrate oxidation, energy metabolism and exercise physiological variables in young males. Materials and methods: Seventeen active males (age = 24.7 ± 6.0years) enrolled to this randomized, triple-blinded, placebo-controlled, crossover trial. Participants attended the laboratory on 4 sessions separated by 72-96h. A submaximal exercise test [to determine maximal fat oxidation (MFO) and the intensity at MFO (FATmax)] followed by a maximal incremental test (to determine VO2max) were performed in a preliminary session. The subsequent sessions only differed in the supplement ingested [LD, HD or placebo (PLA)] and consisted of a steady-state test (60min at FATmax) followed by a maximal incremental test. Energy metabolism, substrate oxidation, heart rate, general (gRPE) and quadriceps (RPEquad) rate of perceived exertion, skin temperature and thermal perception were tested. Results: Clavicle thermal perception was lower in HD compared to PLA and LD (p = 0.04) across time. HD reduced maximum heart rate in comparison to PLA and LD (p = 0.03). LD reported higher general RPE (RPEg) values during the steady-state test compared to PLA and HD across time (p = 0.02). HD and LD elicited higher peak of fat oxidation during the steady-state test compared with PLA (p = 0.05). Intra-test analyses revealed significant differences for fat oxidation (FATox) in favor of HD and LD compared to PLA (p = 0.002 and 0.002, respectively), and for carbohydrate oxidation (CHOox) (p = 0.05) and respiratory exchange ratio (RER) (p = 0.03) for PLA. In the incremental test, only general RPE at 60% of the maximal intensity (W) differed favoring HD (p ≤ 0.05). Conclusion: Therefore, PC may contribute to increase aerobic capacity through the improvement of fat oxidation, maximum heart rate and perceptual responses during exercise.

Four kinds of body temperatures and their relationships with thermal perception

Body temperature serves as the principal factor in thermal perception determination. Current thermal comfort researches mainly focused on skin temperature, while other kinds of body temperatures were often ignored. In laboratory with strictly controlled environment, 26 subjects (13 males and 13 females) remained seated for a duration of 130 min in two thermal environments (19 °C and 35 °C), arranged in a particular order; four kinds of body temperatures (skin temperature, oral temperature, auditory canal temperature and breath temperature) and three kinds of thermal perception votes (thermal sensation, thermal comfort and thermal acceptable) were regularly collected. The analysis results showed that, skin temperature and breath temperature significantly changed with ambient temperature (p < 0.001); the difference between average value of core temperature in two conditions was small (≤0.3 °C), but a significant difference was almost observed in auditory canal temperature of males (p = 0.07). Both skin temperature and breath temperature were significantly related with three subjective votes (p < 0.001), meanwhile, the prediction accuracy of breath temperature for thermal perception was in no way inferior to skin temperature. Although oral temperature and auditory canal temperature had partial significant correlations with thermal perception, they were difficult to be carried out in practical application due to their weak explanatory powers (correlation coefficient <0.3). In summary, this research tried to establish correlation laws between body temperatures and thermal perception votes during a temperature step-change experiment, while finding the potential of utilizing breath temperature for thermal perception prediction, which is expected to be further promoted in the future.

A review of thermal perception and adaptation strategies across global climate zones

Urban thermal environment is very important for human health. Although a growing number of thermal perception surveys had been conducted, the variation of thermal perception associated with background climates remains unclear. Here, we presented a global review of the quantification methods, climate differences, and adaptation strategies for outdoor and indoor thermal comfort during the last 30 years. We found that more than half of current studies were focused on temperate climate zones, particularly in China. The misunderstanding of benchmark terms and inappropriate alternative calculations lead to results bias. Although thermal comfort scale in tropical moist climate zones and thermal acceptance scale in snow and temperate climate zones tend to be refined, applied research remains limited. The results showed that tropical moist climate zones had the highest neutral temperatures while snow climate zones occupied the lowest. The neutral temperature in snow climate zones exhibited the greatest seasonal variations of 6.44 °C for outdoor environments and 6.99 °C for indoor environments. The temperate climate zones had a wider indoor thermal acceptable range while snow climate zones had a wider outdoor acceptable range. This study provides the scientific basis for optimizing management strategies in urban regions to mitigate urban thermal risks.

Experimental assessment of thermal and acoustics interactions on occupant comfort in mixed-mode buildings

Mixed-mode buildings use natural ventilation (NV) through operable building envelopes (e.g., windows) and mechanical air-conditioning (AC) systems to condition indoor spaces with the goal of energy savings without compromising occupant comfort requirements. As a result, occupants within such buildings experience different thermal and acoustic conditions. In mixed-mode buildings, however, there is no clear guideline on assessing or predicting occupants’ thermal perception (e.g., thermal sensation and acceptability) and the interaction effects between thermal and acoustic comfort. This study investigates thermal and acoustic comfort as well as their interaction effects in mixed-mode buildings under NV and AC modes. A field study was conducted in a mixed-mode office building in Singapore with a tropical climate. The results showed that subjects’ actual thermal sensation and thermal acceptability were affected by the operation modes. Elevated air movement by ceiling fans improved subjects’ thermal acceptability, particularly in the NV mode. The results indicated the need for a different thermal comfort model even when switching between NV and AC modes within the same day. Traffic noise also significantly affected thermal sensation and thermal acceptability at noise level higher than 55 dBA. The findings suggest that mixed-mode buildings are potentially applicable in the tropics and provide valuable information on the practical operation of mixed-mode buildings from thermal and acoustic perspectives. Future research needs to investigate how to integrate thermal and acoustic studies and their results into mixed-mode operations to improve building energy efficiency and occupant comfort.

Influences of variable thermal exposures on walking thermal comfort in hot summer - Physio-psychological responses

To improve walkability in warm-biased cities, it is important to study thermal comfort experienced by walking pedestrians in complex urban continuums with variable microclimates. In this study, the heat exchange between a walking human body and its variable ambient was studied by measuring 70 human subjects' skin temperatures, sweating, heart rates, and surveying their mixed thermal perceptions, and monitoring the meteorological parameters in their immediate surroundings in two complex urban continuums. The extent of variable thermal exposures characterized by simultaneously varying wind and solar radiation during walking was described by the index Reverse Dynamic Thermal Environment (R_DTE), and its impacts on the physio-psychological responses of the human subjects were studied. It is concluded that about 36% of produced heat would be accumulated within the body during a 10 min' walking under variable thermal exposures with an air temperature over 28.0 °C. The sweating rate is highly related to the R_DTE rather than the mean skin temperature deviation from the neutral one (ΔTsk). An increased extent of variable thermal exposures significantly improves the thermal comfort when a walking person's skin wettedness (w) is over 0.4, whereas it causes discomfort when w is below 0.2. While some more work are still needed to further understand the dynamic thermal responses, these preliminary findings shed light on assessing and improving walking thermal comfort by creating variable thermal exposures in the urban continuums on hot days.

A Comprehensive Overview of Basic Research on Human Thermal Management in Future Mobility: Considerations, Challenges, and Methods

Thermal management in automobiles is necessary to minimize energy usage while achieving a high level of occupant thermal perception. As the freedom of in-vehicle activity increases with autonomous driving, considering convenience becomes even more important, and, at the same time, the need for thermal management in electric vehicles is expected to increase. While it is necessary to consider the characteristics of the future mobility environment, there is still a lack of research that takes into account these changes in thermal management and proposes future research directions. Therefore, the purpose of this study is to explore basic research directions based on national R&amp;D project cases and to provide a comprehensive overview. The environmental changes that need to be considered in thermal management research include the diversification of future transportation types and usage purpose diversification, the characteristics of electric vehicles, changes in the interior and exterior design of autonomous vehicles, personalized air conditioning environments, and dynamic thermal management according to occupant in-vehicle activity. This study provides an understanding of the overall field, and can help identify challenges, solutions, and ideas. Although this study provides conceptual considerations for research directions, future research is needed to identify detailed factors related to technology, environment, and human factors.