According to the Centers for Disease Control and Prevention (CDC), more people die in the U.S. from heat than from all other natural disasters combined. According to the Environmental Protection Agency (EPA), more than 1,300 deaths per year in the United States are due to extreme heat. Arizona, California and Texas are the three states with the highest burden, accounting for 43% of all heat-related deaths according to the CDC.

Although only 5% of housing in Maricopa County, Arizona, is mobile homes, approximately 30% of indoor heat-related deaths occur in these homes. Thus, the residents of mobile homes in Maricopa County are disproportionately affected by heat. Mobile home residents are extremely exposed to heat due to the high density of mobile home parks, poor construction of dwellings, lack of vegetation, socio-demographic features and not being eligible to get utility and financial assistance.

We researched numerous solutions across different domains that could help build the heat resilience of mobile home residents. As a result we found 50 different solutions for diverse stakeholders, budgets and available resources. The goal of this toolbox is to present these solutions and to explain how to apply them in order to get the most optimal result and build About this Solutions Guide People who live in mobile homes are 6 to 8 times more likely to die of heat-associated deaths. heat resilience for mobile home residents. These solutions were designed as a coordinated set of actions for everyone — individual households, mobile home residents, mobile home park owners, cities and counties, private businesses and nonprofits serving mobile home parks, and other stakeholders — to be able to contribute to heat mitigation for mobile home residents.

When we invest in a collective, coordinated suite of solutions that are designed specifically to address the heat vulnerability of mobile homes residents, we can realize a resilience dividend in maintaining affordable, feasible, liveable housing for the 20 million Americans who choose mobile homes and manufactured housing as their place to live and thrive.

BACKGROUND: The City of Phoenix initiated the HeatReady program in 2018 to prepare for extreme heat, as there was no official tool, framework, or mechanism at the city level to manage extreme heat. The current landscape of heat safety culture in schools, which are critical community hubs, has received less illumination. HeatReady Schools—a critical component of a HeatReady City—are those that are increasingly able to identify, prepare for, mitigate, track, and respond to the negative impacts of schoolgrounds heat. However, minimal attention has been given to formalize heat preparedness in schools to mitigate high temperatures and health concerns in schoolchildren, a heat-vulnerable population. This study set out to understand heat perceptions, (re)actions, and recommendations of key stakeholders and to identify critical themes around heat readiness. METHODS: An exploratory sequential mixed-methods case study approach was used. These methods focused on acquiring new insight on heat perceptions at elementary schools through semi-structured interviews using thematic analysis and the Delphi panel. Participants included public health professionals and school community members at two elementary schools—one public charter, one public—in South Phoenix, Arizona, a region that has been burdened historically with inequitable distribution of heat resources due to environmental racism and injustices. RESULTS: Findings demonstrated that 1) current heat safety resources are available but not fully utilized within the school sites, 2) expert opinions support that extreme heat readiness plans must account for site-specific needs, particularly education as a first step, and 3) students are negatively impacted by the effects of extreme heat, whether direct or indirect, both inside and outside the classroom. CONCLUSIONS: From key informant interviews and a Delphi panel, a list of 30 final recommendations were developed as important actions to be taken to become “HeatReady.” Future work will apply these recommendations in a HeatReady School Growth Tool that schools can tailor be to their individual needs to improve heat safety and protection measures at schools.

Many coastal cities around the world are becoming increasingly vulnerable to natural disasters, particularly flooding driven by tropical storm and hurricane storm surge – typically the most destructive feature of these storms, generating significant economic damage and loss of life. This increase in vulnerability is driven by the interactions between a wide number of complex social and climatic factors, including population growth, irresponsible urban development, a decrease in essential service provision, sea level rise, and changing storm regimes. These issues are exacerbated by the short-term strategic planning that dominates political action and economic decision-making, resulting in many vulnerable coastal communities being particularly unprepared for large, infrequent storm surge events. This lack of preparedness manifests in several ways, but one of the most visible is the lack of comprehensive evacuation and rescue operation plans for use after major storm surge flooding occurs. Typical evacuation or rescue plans are built using a model of a region’s intact road network. While useful for pre-disaster purposes, the immediate aftermath of large floods sees enormous swaths of a given region’s road system flooded, rendering most of these plans largely useless. Post-storm evacuation and rescue requires large amounts of atypical travel through a region (i.e., across non-road surfaces). Traditional road network models (such as those that are used to generate evacuation routes) are unable to conceptualize this type of transportation, and so are of limited utility during post-disaster scenarios. To solve these problems, this dissertation introduces an alternative network conceptualization that preserves important on-network information but also accounts for the possibility of off-network travel during a disaster. Providing this in situ context is necessary to adequately model transportation through a post-storm landscape, one in which evacuees and rescuers are regularly departing from roads and one in which many roads are completely interdicted by flooding. This modeling approach is used to automatically generate routes through a flooded coastal urban area, as well as to identify potentially critical road segments in advance of an actual storm. These tools may help both emergency managers better prepare for large storms, and urban planners in their efforts to mitigate flood damage.

Thermal extremes are responsible for more than 90% of all weather-related deaths in the United States, with heat alone accounting for an annual death toll of 618. With the combination of global warming and urban expansion, cities are becoming hotter and the threat to the well-being of citizens in urban areas is growing. Because people in modern societies (and in particular, vulnerable groups such as the elderly) spend most of their time inside their home, indoor exposure to heat is the underlying cause in a considerable fraction of heat-related morbidity and mortality. Notably, this can be observed in many US cities despite the high prevalence of mechanical air conditioning in the building stock. Therefore, part of the effort to reducing the overall vulnerability of urban populations to heat needs to be dedicated to understanding indoor exposure, its underlying behavioral and physical mechanisms, health outcomes, and possible mitigation strategies. This dissertation is an effort to advance the knowledge in these areas. The cities of Houston, TX, Phoenix, AZ, and Los Angeles, CA, are used as test beds to assess exposure and vulnerability to indoor heat among people 65 and older. Measurements and validated whole-building simulations were used in conjunction with heat-vulnerability surveys and epidemiological modelling (of collaborators) to (1) understand how building characteristics and practices govern indoor exposure to heat among the elderly; (2) evaluate mechanical air conditioning as a reliable protective factor against indoor exposure to heat; and (3) identify potential impacts from the evolving building stock and a warming urban climate. The results show strong associations between indoor heat exposure and certain health outcomes and highlight the vulnerability of elderly populations to heat despite the prevalence of air conditioning systems. Given the current construction practices and urban warming trends, this vulnerability will continue to grow. Therefore, policies promoting climate adaptive buildings features, as well as better access to reliable and affordable AC are needed. In addition, this research draws attention to the significant potential health consequences of large-scale power outages and proposes the implementation of passive survivability in regulations as one important preventative action.

Environmental heat is a growing concern in cities as a consequence of rapid urbanization and climate change, threatening human health and urban vitality. The transportation system is naturally embedded in the issue of urban heat and human heat exposure. Research has established how heat poses a threat to urban inhabitants and how urban infrastructure design can lead to increased urban heat. Yet there are gaps in understanding how urban communities accumulate heat exposure, and how significantly the urban transportation system influences or exacerbates the many issues of urban heat. This dissertation focuses on advancing the understanding of how modern urban transportation influences urban heat and human heat exposure through three research objectives: 1) Investigate how human activity results in different outdoor heat exposure; 2) Quantify the growth and extent of urban parking infrastructure; and 3) Model and analyze how pavements and vehicles contribute to urban heat.

In the urban US, traveling outdoors (e.g. biking or walking) is the most frequent activity to cause heat exposure during hot periods. However, outdoor travel durations are often very short, and other longer activities such as outdoor housework and recreation contribute more to cumulative urban heat exposure. In Phoenix, parking and roadway pavement infrastructure contributes significantly to the urban heat balance, especially during summer afternoons, and vehicles only contribute significantly in local areas with high density rush hour vehicle travel. Future development of urban areas (especially those with concerns of extreme heat) should focus on ensuring access and mobility for its inhabitants without sacrificing thermal comfort. This may require urban redesign of transportation systems to be less auto-centric, but without clear pathways to mitigating impacts of urban heat, it may be difficult to promote transitions to travel modes that inherently necessitate heat exposure. Transportation planners and engineers need to be cognizant of the pathways to increased urban heat and human heat exposure when planning and designing urban transportation systems.

This study investigated the effect of environmental heat stress on physiological and performance measures during a ~4 mi time trial (TT) mountain hike in the Phoenix metropolitan area. Participants (n = 12; 7M/5F; age 21.6 ± 2.47 [SD]) climbed ‘A’ mountain (~1 mi) four times on a hot day (HOT; wet bulb globe temperature [WBGT] = 31.6°C) and again on a moderate day (MOD; WBGT = 19.0°C). Physiological and performance measures were made before and throughout the course of each hike. Mean pre-hike hydration status (urine specific gravity [USG]) indicated that participants began both HOT and MOD trials in a euhydrated state (1.016 ± 0.010 and 1.010 ± 0.008, respectively) and means did not differ significantly between trials (p = .085). Time trial performance was impaired by -11% (11.1 minutes) in the HOT trial (105 ± 21.7 min), compared to MOD (93.9 ± 13.1 min) (p = .013). Peak core temperatures were significantly higher in HOT (38.5 ± 0.36°C) versus MOD (38.0 ± 0.30°C) with progressively increasing differences between trials over time (p < .001). Peak ratings of perceived exertion were significantly higher in HOT (14.2 ± 2.38) compared to MOD (11.9 ± 2.02) (p = .007). Relative intensity (percent of age-predicted maximal heart rate [HR]), estimated absolute intensity (metabolic equivalents [METs]), and estimated energy expenditure (MET-h) were all increased in HOT, but not significantly so. The HOT condition reduced predicted maximal aerobic capacity (CRFp) by 6% (p = .026). Sweat rates differed significantly between HOT (1.38 ± 0.53 L/h) and MOD (0.84 ± 0.27 L/h) (p = .01). Percent body mass loss (PBML) did not differ significantly between HOT (1.06 ± 0.95%) and MOD (0.98 ± 0.84%) (p = .869). All repeated measures variables showed significant between-subjects effects (p < .05), indicating individual differences in response to test conditions. Heat stress was shown to negatively affect physiological and performance measures in recreational mountain hikers. However, considerable variation exists between individuals, and the degree of physiological and performance impairment is probably due, in part, to differences in aerobic fitness and acclimatization status rather than pre- or during-performance hydration status.

The Maricopa County Heat Relief Network (HRN) is an ad-hoc partially self-organized network with some attributes of hierarchical coordination that forms each year to provide heat relief and hydration to residents in need by operating as cooling centers. These HRN organizations are a collection of non-profit, governmental and religious organizations. This dissertation looks at the HRN from a complexity governance perspective and engaged different parts of the network in interviews to learn more about their perspective in delivering heat relief. Further, participatory modeling with a prototype agent based model was done with the HRN coordinating agencies to look for emergent outcomes in the HRN system and learn from their perspective. Chapter one evaluates organizational theory and complexity with climate adaptation, hazard preparedness and resilience in the HRN. Chapter two presents results from interviews with HRN facility managers and evaluates their perspective on how they function to offer heat relief. Chapter three finds that the HRN is a good example of complexity governance when engaged through a participatory agent based modeling approach. Chapter four engages the HRN coordinators in participatory agent based modeling interviews to increase their systems level awareness, learn about their perspective on heat relief delivery, and how the system can be improved. Chapter five looks across the different levels of the HRN investigated, the facility managers and coordinators, for differences and similarities in perspectives. The research conducted in this dissertation shows different levels of systems awareness of the different parts of the HRN and how participatory modeling can be used to increase systems awareness. Results indicate that there was very little horizontal network connection between HRN facility managers and most of the interaction was vertically coordinated indicating opportunities for increased network communication in the future both horizontally and vertically if communication interventions were put in place.

Trees serve as a natural umbrella to mitigate insolation absorbed by features of the urban environment, especially building structures and pavements. For a desert community, trees are a particularly valuable asset because they contribute to energy conservation efforts, improve home values, allow for cost savings, and promote enhanced health and well-being. The main obstacle in creating a sustainable urban community in a desert city with trees is the scarceness and cost of irrigation water. Thus, strategically located and arranged desert trees with the fewest tree numbers possible potentially translate into significant energy, water and long-term cost savings as well as conservation, economic, and health benefits. The objective of this dissertation is to achieve this research goal with integrated methods from both theoretical and empirical perspectives.

This dissertation includes three main parts. The first part proposes a spatial optimization method to optimize the tree locations with the objective to maximize shade coverage on building facades and open structures and minimize shade coverage on building rooftops in a 3-dimensional environment. Second, an outdoor urban physical scale model with field measurement is presented to understand the cooling and locational benefits of tree shade. The third part implements a microclimate numerical simulation model to analyze how the specific tree locations and arrangements influence outdoor microclimates and improve human thermal comfort. These three parts of the dissertation attempt to fill the research gap of how to strategically locate trees at the building to neighborhood scale, and quantifying the impact of such arrangements.

Results highlight the significance of arranging residential shade trees across different geographical scales. In both the building and neighborhood scales, research results recommend that trees should be arranged in the central part of the building south front yard. More cooling benefits are provided to the building structures and outdoor microclimates with a cluster tree arrangement without canopy overlap; however, if residents are interested in creating a better outdoor thermal environment, open space between trees is needed to enhance the wind environment for better human thermal comfort. Considering the rapid urbanization process, limited water resources supply, and the severe heat stress in the urban areas, judicious design and planning of trees is of increasing importance for improving the life quality and sustaining the urban environment.