Heat Stress Vulnerability Research Articles

High‐Resolution Modeling and Projecting Local Dynamics of Differential Vulnerability to Urban Heat Stress

AbstractClimate change‐induced heat stress has significant effects on human health, and is influenced by a wide variety of factors. Most assessments of future heat‐related risks however are based on coarse resolution projections of heat hazards and overlook the contribution of relevant factors other than climate change to the negative impacts on health. Research highlights sociodemographic disparities related to heat stress vulnerability, especially among older adults, women and individuals with low socioeconomic status, leading to higher morbidity and mortality rates. There is thus an urgent need for detailed, local information on demographic characteristics underlying vulnerability with refined spatial resolution. This study aims to address the research gaps by presenting a new population projection exercise at high‐resolution based on the Bayesian modeling framework for the case study of Madrid, using demographic data under the scenarios compatible with the Shared Socioeconomic Pathways. We examine the spatial and temporal distribution of population subgroups at the intra‐urban level within Madrid. Our findings reveal a concentration of vulnerable populations, as measured by their age, sex and educational attainment level in some of the city's most disadvantaged neighborhoods. These vulnerable clusters are projected to widen in the future unless a sustainable trajectory is realized, driving vulnerability dynamics toward a more uniform and resilient change. These results can guide local adaptation efforts and support climate justice initiatives to protect vulnerable communities in urban environments.

Sex differences in heat stress vulnerability among middle-aged and older adults (PSU HEAT Project).

Individuals over the age of 65 yr are the most vulnerable population during severe environmental heat events, experiencing worse health outcomes than any other age cohort. The risk is greater in older women than in age-matched men; however, whether that reflects a greater susceptibility to heat in women, or simply population sex proportionality, is unclear. Seventy-two participants (29 M/43 F) aged 40-92 yr were exposed to progressive heat stress at a metabolic rate designed to reflect activities of daily living. Experiments were conducted in both hot-dry (HD; up to 53°C; ≤25% rh) and warm-humid (WH; ∼35°C; ≥50% rh) environments. After critical limits were determined for each condition, forward stepwise multiple linear regression analyses were conducted with net metabolic rate (Mnet) and age entered into the model first, followed by sex, body mass (mb), maximal oxygen consumption (V̇o2max), body surface area, and LDL cholesterol. After accounting for Mnet and age, sex further improved the regression model in the HD environment ([Formula: see text] = 0.34, P < 0.001) and the WH environment ([Formula: see text] = 0.36, P < 0.005). Sex explained ∼15% of the variance in critical environmental limits in HD conditions and 12% in WH conditions. Heat compensability curves were shifted leftward for older women, indicating age- and sex-dependent heat vulnerability compared with middle-aged women and older men in WH (P = 0.007, P = 0.03) and HD (P = 0.001, P = 0.01) environments. This reflects the heterogeneity of thermal-balance thresholds associated with aging relative to those seen in young adults and suggests that older females are more vulnerable than their age-matched male counterparts.NEW & NOTEWORTHY In contrast to young adults, there are sex differences in critical environmental limits in middle-aged and older adults. Older women exhibit lower critical environmental limits in both humid and dry extreme environments demonstrated by a leftward shift in heat compensability curves. These data confirm a true sex difference in heat vulnerability of older adults and support the epidemiological mortality data from environmental heat waves.

Mapping the heat stress vulnerability landscape of Agartala City, India

Mapping the heat stress vulnerability landscape of Agartala City, India

Spatio-temporal urban land surface temperature variations and heat stress vulnerability index in Thiruvananthapuram city of Kerala, India

ABSTRACT Land use/Land cover (LU/LC) modifications leads to rise in surface temperature is a global concern. This study investigates the effects of LU/LC changes in Land Surface Temperature (LST) variations and effects of Urban Heat Island (UHI) in Thiruvananthapuram city. Furthermore, the study proposed a novel heat stress vulnerability index (HSVI) using Analytical Hierarchy Process (AHP) method. Results shows that transformation of all land uses is to built-up areas, which shows an increase of +118.46% where as others such as vegetation (-24.27%), open area (-64.315) and waterbody (-43.88%) shows drastic decrease over 34 years. The relationship between Normalized Difference Vegetation Index and LST shows a significant change with R2 values between 0.223 in 1988, 0.382 in 2000 and 0.253 in 2022. Moreover, this also contributed to the increase of the mean LST of 26.96 ºC in 1988 to 28.52 ºC in 2022. HSVI of the study indicates that 30.83% of the study area is categorized as very low heat stress vulnerable area followed by 37.22% area in low heat stress vulnerability, 17.88% in moderate heat stress vulnerability, 8.87% in high heat stress vulnerability and 5.19% of the area falling in very high heat stress Vulnerability class.

Thermal limits of survival and reproduction depend on stress duration: A case study of Drosophila suzukii.

Studies of ectotherm responses to heat extremes often rely on assessing absolute critical limits for heat coma or death (CTmax), however, such single parameter metrics ignore the importance of stress exposure duration. Furthermore, population persistence may be affected at temperatures considerably below CTmax through decreased reproductive output. Here we investigate the relationship between tolerance duration and severity of heat stress across three ecologically relevant life-history traits (productivity, coma and mortality) using the global agricultural pest Drosophila suzukii. For the first time, we show that for sublethal reproductive traits, tolerance duration decreases exponentially with increasing temperature (R2 > 0.97), thereby extending the Thermal Death Time framework recently developed for mortality and coma. Using field micro-environmental temperatures, we show how thermal stress can lead to considerable reproductive loss at temperatures with limited heat mortality highlighting the importance of including limits to reproductive performance in ecological studies of heat stress vulnerability.

Heat stress vulnerability and critical environmental limits for older adults

The present study examined heat stress vulnerability of apparently healthy older vs. young adults and characterized critical environmental limits for older adults in an indoor setting at rest (Rest) and during minimal activity associated with activities of daily living. Critical environmental limits are combinations of ambient temperature and humidity above which heat balance cannot be maintained (i.e., becomes uncompensable) for a given metabolic heat production. Here we exposed fifty-one young (23 ± 4 yrs) and 49 older (71 ± 6 yrs) adults to progressive heat stress across a wide range of environments in an environmental chamber during Minimal Activity (young and older subjects) and Rest (older adults only). Heat compensability curves were shifted leftward for older adults indicating age-dependent heat vulnerablity (p < 0.01). During Minimal Activity, critical environmental limits were lower in older compared to young adults (p < 0.0001) and lower than those at Rest (p < 0.0001). These data document heat vulnerability of apparently healthy older adults and define critical environmental limits for indoor settings in older adults at rest and during activities of daily living, and can be used to develop evidence-based recommendations to minimize the deleterious impacts of extreme heat events in this population.

Heat Stress Vulnerability Among Small-Scale Factory Workers and Adaptive Strategies in Ahmedabad: a Cross Sectional Study

Introduction: Global warming is likely to affect certain groups such as workers in heat-producing industries. With limited research exploring such an important area, this study aimed to explore the heat stress vulnerability and adaptive strategies of indoor small-scale factory workers. Methods: This was a cross-sectional study and a mixed-method approach was used. The study setting was small-scale factory units. The quantitative component included environmental and biological monitoring from six units of steel rolling mills and foundry in the summer and winter seasons. The study was conducted during the period of November-2018 and May 2019. Heat stress was measured among workers using a portable Wet Bulb Globe Temperature (WBGT) meter. The physiological parameters of workers were also measured. The qualitative component included in-depth interviews of workers and supervisors from eleven units. Results: The maximum temperatures recorded at steel rolling mills and foundry crossed Occupational Safety and Health Administration (OSHA) threshold (27.5℃) in summer as well as winter. The mean WBGT at the steel rolling mill recorded 31.5℃. The physiological measurements of workers also crossed the threshold level for heart rate and oral temperature in steel rolling and foundry units. The units had mechanisms to dissipate heat but lack a temperature monitoring mechanism inside the units. The workers wore lighter or fewer clothes as an adaptive measure but uncomfortable PPEs in foundry units were avoided. Conclusion: Heat stress in small-scale industry units was found high and there is a high need to develop specific strategies for such vulnerably high heat-exposed groups.

Heat Stress Vulnerability of Populations and Role of Urban Heat Island

A city's ecology and energy use can be affected by an urban heat island (UHI). However, its role in exacerbating populations' heat stress has been extensively studied. This study reviewed and summarized the literature on the UHI, its causes, and its effects. After that, the characteristics of population heat stress vulnerability are examined. The results of studies on UHI, its health effects, and potential mitigation tactics in existing settlements show the necessity of examining various relationships between UHI and the locations of susceptible populations and possible responses. By examining literature from related domains, the present study intends to identify the research potential and convince researchers about the necessity of such a study in the urban area, especially in developing nations, since such case studies were only a few. Further, the study highlighted the relevance of urban planning to mitigate UHI. A fundamental examination of a city's urban climate can be the initial step in creating urban design standards, followed by research and models considering socio-economic and environmental elements.

Space poverty driving heat stress vulnerability and the adaptive strategy of visiting urban parks

Climate change and urbanisation have exacerbated social inequities. Increasing urban heat has made high-density housing units a vulnerability hotspot. Alternatives to extended air-conditioning are required. This research sought evidence on using urban parks as a sustainable alternative by low-income households deprived of adequate living space. We interviewed occupants of tiny flats (approx. 10 m2), known as subdivided units, and compared their park visiting routines and thermal comfort practices with other urban dwellers in Hong Kong. The substandard conditions of these small units have contributed to dwellers' sensitivity and lower capacity to adapt to summer heat, resulting in heat-related illness. The space-poor households have taken a wider range of adaptive actions and visited urban parks more frequently for cooling. Their higher mobility between home and nearby parks has shortened their home-stay time that would otherwise demand residential space cooling. The findings are important for reconsidering and redressing the uneven distribution of urban green spaces. Poor housing conditions and heat stress have forced disadvantaged households to seek refuge from natural cool spaces, such as vegetated and shaded areas of urban parks. Measures for increasing their accessibility, availability and capacity for heat mitigation are conducive to pro-poor and pro-climate spatial planning.

Linking science and practice in participatory future-oriented assessment and planning of human heat stress vulnerability in Bonn, Germany

The juxtaposition of climate change and development changes is vital for understanding the future impacts of heat stress in urban areas. However, an approach that considers the relationship between climatic factors and socio-economic vulnerability in a forward-looking and stakeholder-involved manner is challenging. This article demonstrates the application of a future-oriented vulnerability scenarios approach to address human heat stress in Bonn, Germany, in 2035. The study highlights the interplays between climate trajectories and heat exposure associated with urban development scenario corridors. Moreover, this method allows for changing combinations of intersections and conditionalities of projected individual socio-economic vulnerability indicators in response to social and climate governance. However, this study found that a conventional structure within city departments might limit this integrative approach in practice. Thus, the theoretical background and the concept of alternative futures and uncertainties should be the focus of communication with practitioners to maximize the utilization of the results.

Climate change-mediated heat stress vulnerability and adaptation strategies among outdoor workers

ABSTRACT The study examined the effect of heat stress on the well-being of outdoor workers and their coping strategies. A cross-sectional survey study was conducted between September 2019 and December 2019 to collect data from outdoor workers including hawkers and traffic wardens from 13 urban areas (N = 322) and analyzed using SPSS v.23. The results of the study show that most of the outdoor workers were in a good health state based on their self-health assessment. However, the respondents expressed concerns and symptoms of heat stress including heat cramps, heat exhaustion, heat stroke and sleep disorders. The findings also show that male outdoor workers were 1.3 times more likely than females to be affected by heat stress. Respondents in their 20s were more likely to be affected by heat stress, as a result of temperatures and humidity conditions, than those in their 30s (OR = 0.389, CI = 0.158–0962) and 40s (OR = 0.395, CI = 0.147–1.063). Coping strategies identified include the use of breathable cotton attires, drinking a lot of water, hiding under shades and reducing outdoor activity intermittently.

Mapping Heat Stress Vulnerability and Risk Assessment at the Neighborhood Scale to Drive Urban Adaptation Planning

Climate change is one of the most complex issues of the 21st century, and even though there is general consensus about the urgency of taking action at the city level, the planning and implementation of adaptation measures is advancing slowly. The lack of data and information to support the planning process is often mentioned as a factor hampering the adaptation processes in cities. In this paper, we developed and tested a methodology for heat stress vulnerability and risk assessment at the neighborhood scale to support designers, planners, and decision makers in developing and implementing adaptation strategies and measures at the local level. The methodology combines high-resolution spatial information and crowdsourcing geospatial data to develop sensitivity, adaptive capacity, vulnerability, exposure, and risk indicators. The methodology is then tested on the urban fabric of the city of Padova, Italy. Our results show that different vulnerability and risk values correspond to different typologies of urban areas. Furthermore, the possibility of combining high-resolution information provided by the indicators and land use categories is of great importance to support the adaptation planning process. We also argue that the methodology is flexible enough to be applied in different contexts.

MI-Environment: Geospatial patterns and inequality of relative heat stress vulnerability in Michigan.

Heat stress causes morbidity and mortality and is increasing with climate change. Heat stress can pose particular challenges in northern regions not well adapted to heat. To assist decision makers, we identified the relative vulnerability of census tracts within Michigan to factors that increase exposure to heat stress or reflect susceptibilities in the population based on a California heat vulnerability index. In the MI-Environment assessment, we used a Geographic Information System (GIS) to combine future ensemble climate model projections to create a total of 9 geospatial and demographic variables. As part of a broader planned cumulative environmental exposure assessment, the statewide heat vulnerability index (HVI) maps display the location and relative magnitude of exposure on three metrics: built environment (Place), future expected long-term temperature averages (Temperature), and population susceptibility (People). We observed varied and distinct patterns for each of the three component indices. We assessed how equitably those exposures are distributed by racial and socioeconomic factors. This analysis showed that each of the component indices and the aggregate HVI are disproportionately distributed along racial and socioeconomic lines in Michigan. Census tracts with higher percentages of people of color had larger exposure to HVI factors with a deviation from equity of -0.115 [95% CI -0.108, -0.122]. Similarly, for census tracts with higher percentage of people experiencing poverty, the deviation from equity was -0.101 [95% CI -0.094, -0.107]. The MI-Environment visualization tool can help communities prepare for climate change and resolve inequities by identifying census tracts with the most vulnerable residents and highest potential exposures.

Heat stress vulnerability and risk at the (super) local scale in six Brazilian capitals

Brazilian cities host 86% of the country’s population and have been more intensely hit by rising temperatures than the average of cities across the world over the last century. Nevertheless, assessments of the vulnerability of Brazilian urban dwellers to urban heat islands (UHI) are scarce. In this study, we take advantage of the availability of high-resolution data to calculate the heat stress vulnerability and risk indexes (HSVI and HSRI, respectively) for people inhabiting six Brazilian metropolitan areas—Manaus, Natal, Vitoria, Sao Paulo, Curitiba, and Porto Alegre. The indexes are calculated by mathematically relating indicators of exposure (distribution of >65-year-old elderly people), sensitivity/adaptive capacity (human development index, HDI), and hazard (surface temperature). The resulting HSVI maps reflect the socioeconomic (HDI) differences found among the studied cities, with the most vulnerable people located in the poorest neighborhoods in Manaus (0.720) and Natal (0.733), distributed among lower- and mid-class zones in Sao Paulo (0.794) and Vitoria (0.772), or invariably located in the wealthy zones of Curitiba (0.783) and Porto Alegre (0.762). Two distinct patterns are identified for the HSRI: in Sao Paulo, Vitoria, Curitiba, and Porto Alegre, high and very high risks are found in the wealthy zones of the cities, whereas in Natal and Manaus, high and very high risks are encountered in the poorly developed city zones, a result that was strongly driven by the UHI pattern. Better communication of heat stress risk and the improvement of city greenness should be the focus of near-term adaptation strategies for the mapped vulnerable population.

Heat Stress Perception among Native and Migrant Workers in Italian Industries-Case Studies from the Construction and Agricultural Sectors.

Climate change will increase the frequency and severity of hazard events such as heat waves, with important effects in several European regions. It is of importance to consider overall effects as well as specific impact on vulnerable population groups such as outdoor workers. The agricultural and construction sectors represent two strategic occupational fields that in relatively recent years involve an increasing number of migrant workers, and therefore require a better management of cultural aspects, that may interact with and impact on heat-related health risk. For this reason, the present study evaluated heat-stress perception and management among native and immigrant workers in Europe. As part of the EU’s Horizon 2020 HEAT-SHIELD project (grant agreement No. 668786), two agricultural and one construction companies, traditionally employing migrant workers, were evaluated with a questionnaire survey during the summer months of 2017. The data collected (104 case studies) were analyzed using descriptive statistics (Chi-squared tests) and the analysis of variance was performed with ANOVA test. From the results, migrant workers declared that work required greater effort than do native Italian workers (χ2 = 17.1, p = 0.001) but reported less impact from heat on productivity (χ2 = 10.6; p = 0.014) and thermal discomfort. In addition, migrant workers were mainly informed through written or oral communications, while native workers received information on heat-health issues through training courses. These findings are of importance for future information and mitigation actions to address socio-cultural gaps and reduce heat-stress vulnerability.

Quantification and evaluation of intra-urban heat-stress variability in Seoul, Korea.

This study quantifies heat-stress hazard (air temperature), vulnerability (heat vulnerability index and age score), and risk (heat-related mortality) on the district scale in Seoul, Korea, for a comprehensive heat-stress impact assessment. Moreover, the heat-stress impact assessment is evaluated by checking the spatial consistency between heat-stress hazard, vulnerability, and risk, which was rarely done before. We applied numerical and geo-empirical models to simulate the spatial pattern of heat-stress hazard. For heat-stress vulnerability, we used demographic and socioeconomic factors. Heat-related mortality was estimated based on an event-based heat-stress risk analysis. Results are that heat-stress hazard, vulnerability, and risk are spatially variable in Seoul. The highest heat-stress hazard was detected in the districts Mapo, Yeongdeungpo, and Yangcheon, the highest vulnerability in Jongno and the highest risk in Jongno and Yangcheon. The different components (heat-stress hazard, vulnerability, and risk) and variables (heat vulnerability index and percentage of seniors) showed different spatial patterns. Knowledge about the causes of higher heat-stress risk, either the hazard or vulnerability, is helpful to design tailored adaptation measures that focus on the reduction of thermal loads or on the preparation of the vulnerable population. The evaluation showed that heat-stress vulnerability and hazard explain the spatial pattern of risk only partly. This highlights the need to evaluate heat-stress impact assessment systems to produce reliable urban heat-stress maps.

Locating Urban Heat Stress Vulnerability: A GIS-based Spatial Cluster Analysis of Urban Heat Load, the Elderly and Accessibility of Urban Green Spaces

Locating Urban Heat Stress Vulnerability: A GIS-based Spatial Cluster Analysis of Urban Heat Load, the Elderly and Accessibility of Urban Green Spaces

Urban Heat Stress Vulnerability in the U.S. Southwest: The Role of Sociotechnical Systems

Heat vulnerability of urban populations is becoming a major issue of concern with climate change, particularly in the cities of the Southwest United States. In this article we discuss the importance of understanding coupled social and technical systems, how they constitute one another, and how they form the conditions and circumstances in which people experience heat. We discuss the particular situation of Los Angeles and Maricopa Counties, their urban form and the electric grid. We show how vulnerable populations are created by virtue of the age and construction of buildings, the morphology of roads and distribution of buildings on the landscape. Further, the regulatory infrastructure of electricity generation and distribution also contributes to creating differential vulnerability. We contribute to a better understanding of the importance of sociotechnical systems. Social infrastructure includes codes, conventions, rules and regulations; technical systems are the hard systems of pipes, wires, buildings, roads, and power plants. These interact to create lock-in that is an obstacle to addressing issues such as urban heat stress in a novel and equitable manner.

Review of Climate Change Adaptation and Social Protection Policies of Ghana

Smallholder farming has become a significant livelihood coping strategy of the population in Ghana. However, in the last decade the upsurge of climate change and the effect of heat stress vulnerability on smallholder farmers in Northern Ghana are alarming. This article investigates the chances of using social protection and climate change adaptation policies towards the management of risks associated with heat stress emanating from climate change. It reviews salient literature on heat stress, social protection, and climate change policies and develops a model upon which both domestic and international interest in climate and social protection policies of Ghana and Sub-Sahara Africa can reduce or aggravate heat stress impacts on smallholder farmers both at their working environment and at household level. It exemplifies the efficacy of the strength of social protection and climate change adaptation policies in Ghana and its impacts on vulnerable rural smallholder farmers and how such situation is replicated in many parts of Africa. It outlines further measures that can be undertaken by governments and international donor agencies to revamp the destitution of smallholder farmers to climate change and heat stress in African region.

Critical Body Temperature Profile as Indicator of Heat Stress Vulnerability

Extreme climatic heat is a major health concern among workers in different occupational pursuits. People in the regions of western India confront frequent heat emergencies, with great risk of mortality and morbidity. Taking account of informal occupational groups (foundry and sheet metal, FSM, N=587; ceramic and pottery, CP, N=426; stone quarry, SQ, N=934) in different seasons, the study examined the body temperature profiling as indicator of vulnerability to environmental warmth. About 3/4th of 1947 workers had habitual exposure at 30.1-35.5°C WBGT and ~10% of them were exposed to 38.2-41.6°C WBGT. The responses of FSM, CP and SQ workers indicated prevailing high heat load during summer and post-monsoon months. Local skin temperatures (T(sk)) varied significantly in different seasons, with consistently high level in summer, followed by post-monsoon and winter months. The mean difference of T(cr) and T(sk) was ~5.2°C up to 26.7°C WBGT, and ~2.5°C beyond 30°C WBGT. Nearly 90% of the workers had T(cr) within 38°C, suggesting their self-adjustment strategy in pacing work and regulating T(cr). In extreme heat, the limit of peripheral adjustability (35-36°C T(sk)) and the narrowing down of the difference between T(cr) and T(sk) might indicate the limit of one's ability to withstand heat exposure.