About

Ladd Keith, Ph.D., is an associate professor in the School of Landscape Architecture and Planning at the University of Arizona. He serves as the Director of the Heat Resilience Initiative and is a faculty research associate at the Udall Center for Studies in Public Policy. His transdisciplinary research focuses on heat planning, policy, and governance to enhance heat resilience in communities, regions, and nations worldwide. Dr. Keith is the UA lead of the Southwest Urban Corridor Integrated Field Laboratory (SW-IFL), co-lead of the Center for Heat Resilient Communities, and the heat research lead of the Climate Assessment for the Southwest (CLIMAS). He also contributes to several other initiatives aimed at addressing extreme heat and climate resilience, and serves on the Management Committee for the Global Heat Health Information Network, a joint initiative of the World Health Organization and the World Meteorological Organization.

Research topics

• Environmental science
• Business
• Geography
• Computer Science
• Environmental resource management
• Environmental planning
• Finance
• Physics
• Ecology
• Atmospheric sciences
• Climatology
• Meteorology
• Biology

Selected publications

• Role of Public Health in Wildfire: Lessons from the Field

  EcoHealth · 2026-03-26

  articleOpen accessSenior author

  Risk of human exposure to wildfire is increasing, with detrimental effects on human health. Public health is uniquely placed to support community resilience during wildfire events, but the nature of public health's role remains unclear. Participants were recruited from government health entities in Southwestern counties that had previously experienced wildfires or significant smoke exposure. We used semi-structured interviews to understand perceptions and actions around wildfire response. To support public health practitioners' role in proactive and comprehensive wildfire outreach, evidence to support the interventions is summarized. In June 2024, 14 individuals from 12 organizations in Arizona and New Mexico were interviewed. Three themes emerged: (1) clear and consistent messaging, (2) connecting people to resources, and (3) flexibility supports capacity. There is evidence to support the need for clear and consistent messaging, but limited evidence on best practices for difficult to reach communities. More evidence is needed for which interventions work during a wildfire, adaptations for marginalized communities, and interventions when facing multiple hazards. Public health is shifting from passive education to proactive, comprehensive wildfire outreach. As part of a cross-sectoral response, public health is integral to disseminating consistent and clear messaging. Further, public health has an important role in facilitating access to resources, though there is a need for efficacy studies of what resources, under which circumstances, and for which populations. Finally, any successful response will require cooperation across sectors and community partners. Within the funding landscape for public health entities, flexibility in resource allocation is critical.

  PublisherOA PDFDOI

• Commentary: Our “heatshed” moment is now

  Journal of Urban Affairs · 2026-04-29

  article1st authorCorresponding
  PublisherDOI

• Evaluating the impacts of cool pavement on pedestrian-level heat stress indicators

  Discover Cities · 2026-03-13

  articleOpen access

  Extreme heat is an increasing hazard in communities across the world due to climate change and urbanization patterns resulting in urban heat. Transportation infrastructure, such as road pavement, is a well-known contributor to the urban heat island effect. Engineered pavement coatings, known as cool pavement, reflect light and heat to reduce the thermal load of roads and reduce urban heat, but their effect on heat stress, and therefore human thermal comfort, of travelers such as pedestrians, cyclists, and transit riders, is still an underexplored area. The City of Tucson, Arizona, applied a cool pavement pilot of the PlusTi asphalt rejuvenator in 2021 as a part of its Parks and Connections Bond. Previous studies on cool pavement asphalt rejuvenators have found inconsistencies in the magnitude of their cooling properties in the lab versus real-world settings. We conducted a before-after natural study design to evaluate the impacts of the cool pavement application on indicators of heat stress, including ambient air temperature (TA) and wet bulb globe temperature (WBGT). Once temporal autocorrelation is accounted for, we found that the PlusTi asphalt rejuvenator resulted in 0.11 °C (0.2 °F) more TA observed and no statistical difference in WBGT, indicating minimal negative impacts to heat stress indicators in this natural experiment setting. Continued evaluation of cool pavement products is critical to better understand their potential in mitigating urban heat and ensuring minimal negative impacts on heat stress indicators.

  PublisherOA PDFDOI

• A pilot study exploring the effect of vehicular waste heat on personal heat exposure

  2026-01-17

  articleOpen accessSenior author

  Understanding the causes of heat in various microclimates in cities is vital to improving human thermal comfort and health in outdoor spaces. This pilot study uses an experimental design to evaluate microclimate heat risk – including ambient air temperature (TA) and wet bulb globe temperature (WBGT) – and approximate personal heat exposure of people 1.5-3.0 meters (5-10 feet) away from idling vehicles. These measurements were taken at a University of Arizona covered parking garage in June 2022 to investigate personal heat exposure attributable to vehicular waste heat while also minimizing the effect of solar radiant heat and wind. We used Kestrel 5400 devices to document the waste heat effects of a fleet of six identical gasoline-powered vehicles on the surrounding microclimate by collecting TA, wind velocity, and WBGT. When compared to the control, as well as comparing a period when engines were not idling, we found a strong correlation between vehicle presence, TA, and WBGT. Specifically, ordinary least-mean square (OLS) modeling shows an additional TA per minute increase of 0.006°C (a 25% increase) per minute when the vehicles are on and idling versus 0.024°C per minute increase that occurs from expected background morning temperatures when the vehicle effect is removed. Until we transition to an electric fleet and increase use of alternative modes of transportation, these findings can help inform how transportation professionals design the built environment and manage traffic and transit during summer months to prevent excessive heat exposure for pedestrians, cyclists, transit riders, and other individuals near idling vehicles.

  PublisherOA PDFDOI

• Evaluating Urban Heat Mitigation across Networks of Plans

  UNC Libraries · 2026-04-03

  articleOpen access

  Cities must equitably plan for heat resilience as heat risks increase but lack integrated approaches to coordinate strategies across community plans and prioritize heat mitigation for the most vulnerable communities. We adapted the Plan Integration for Resilience Scorecard™ (PIRS™) methodology, originally developed for flood hazards, to heat and piloted it in five geographically diverse U.S. cities. We used PIRS™ for Heat to analyze how policies across community plans would affect urban heat and compared spatial patterns in policy attention with indicators of vulnerability. We find that heat mitigation policies are not targeting the highest heat risk areas.

  PublisherDOI

• Trends and Disparities in Heat-Related Emergency Medical Services Activations

  JAMA · 2026-02-04

  articleOpen access

  This study compares US sociodemographic and geographic trends in heat-related and non–heat-related emergency medical services (EMS) activations from 2019 to 2024.

  PublisherOA PDFDOI

• A comparison of plan integration for flood and heat resilience: A case study of Baltimore, Maryland

  International Journal of Disaster Risk Reduction · 2025-06-09 · 5 citations

  article
  PublisherDOI

• Too hot to handle: Assessing practitioner climate service needs to advance heat resilience

  Climate Services · 2025-08-19

  articleOpen access

  • Barriers to extreme heat adaptation are varied and widely distributed. • Heat practitioners are using climate information to both mitigate and manage heat. • There is a need for information to communicate heat risks to the public, which can directly save lives. • No actor consistently ‘owns’ heat, making it difficult to identify for whom heat-related climate services should be targeted. Extreme heat is deadly and it is disproportionately experienced by lower-income, minority, and marginalized community members. Heat practitioners are faced with the dual challenges of taking action to mitigate the level of heat experienced by local residents while preparing communities to manage unavoidable levels of elevated warming. In response to a lack of in-depth information about heat practitioner needs, this work aims to advance our understanding of how efforts to improve climate services may contribute to more effective extreme heat planning and decision-making in the United States. Through a two-round, mixed-methods approach that employed group interviews and a survey, we engaged with 144 heat practitioners from 40 states and Washington, DC. We found that the biggest barriers to extreme heat planning and implementation are a lack of perceived risk and a lack of internal staff capacity, and that practitioners would welcome additional heat related information and tools. The two practitioner “needs” that respondents considered to be most impactful are: regularly updated local-scale extreme heat data collection, and improved information about how extreme heat impacts different systems. We found significant differences in the perceived impactfulness of interventions based on whether a respondent was from a rural or urban area and also based on their level of educational attainment. Climate-induced extreme heat is deadly and disproportionately impacts lower-income, minority, and marginalized community members. People working for local and regional governments are responsible for making decisions and implementing actions to reduce the impacts of extreme heat in their communities. Those tasked with that work are referred to here as heat practitioners. To understand their needs we conducted a series of interviews and a survey that engaged over 140 heat practitioners from 40 states and Washington, DC. In this paper we share our findings that bring an in-depth understanding of climate service needs specific to those working to protect people from extreme heat. An important finding from our work is that climate services cannot be just about more information, there is a need for building adaptive capacity and support to overcome complex barriers. Specifically we see a clear need to address the silos heat practitioners find themselves in. Additionally, by elevating the importance of heat within communities practitioners will have an easier time working to manage and mitigate this threat. We find a strong call for better information that is tailored to local contexts. Heat practitioners said that the most impactful thing that would benefit their work is updated local-scale extreme heat data collection and on-the-ground monitoring. Another highly localized data need was information about the relationship between urban design and extreme heat. We also heard that information should be about specific actions heat practitioners could take to address this threat. One specific example is the request for information about the relative effectiveness of nature-based solutions. Heat practitioners also noted that translation of information was crucial for their work. They specifically note a need for translations that connect extreme heat to risk. For example heat practitioners consider a regionally specific heat index as potentially having a high level of impact which indicates the need for translation efforts. The need for translation is also made clear when we hear quotes like “Instead of giving me the data, show me what I can do with the data.” Finally, we observed a need for climate services to be specific to the circumstances of different places. Respondents working in urban areas were more likely to indicate that additional information would be impactful to their work. This difference could be addressed by developing information that is more clearly tailored to and relevant for rural areas. Additionally, we observed different needs between those with postgraduate education and those with bachelor’s degrees or less. This education divide could be addressed by improved access to education as well as different types of information provided to each group. Heat practitioners were somewhat siloed into those that focus on mitigating heat and those that focus on management of heat. This could be addressed by both working to bridge these two groups and by developing services specific to each type of heat practitioner.

  PublisherDOI

• Planning for heat resilience in increasingly vulnerable cities: A case study of Vienna, Austria

  Sustainable Cities and Society · 2025-07-26 · 5 citations

  articleSenior author
  PublisherDOI

• Rural heat health disparities: Evidence from the U.S. National Emergency Medical Services Information System (NEMSIS)

  The Journal of Climate Change and Health · 2025-03-01 · 5 citations

  articleOpen access

  Increasing average temperatures and extreme heat events due to climate change have adverse effects on human health. Previous studies focus on the heat impacts in urban areas due to the focus on the greater population and urban heat island effect, but this tendency results in the effect of heat on rural health being overlooked. Using the National Emergency Medical Services Information System (NEMSIS) data from 2021 to 2023, this study compares heat-related illness (HRI) in urban and rural areas of the U.S. We found the odds of EMS events in an urban area resulting with a positive outcome for the patient was 1.24 times that of EMS events in rural areas. This urban-rural disparity was not equal across regions with the odds of EMS events to rural areas of the Western U.S. resulting with a positive outcome for the patient was 54 % less than that for urban areas. This critical evidence of a rural-urban heat health disparity calls attention to the impact of climate change-fueled heat impacts on health in communities of all sizes, and a need for more rural heat resilience research to inform practice. • Studies on the health effects of heat tend to overlook rural areas. • Comparing EMS heat related events, the odds an urban event resulting in a positive outcome was 1.24 times that of patients in rural area. • This urban-rural disparity was more evident in the Western U.S.

  PublisherDOI

Frequent coauthors

• Heidi E. Brown

  University of Arizona

  9 shared

• Sara Meerow

  Arizona State University

  8 shared

• Erika Austhof

  University of Arizona

  7 shared

• Ben McMahan

  6 shared

• Mona Arora

  University of Arizona

  5 shared

• Gigi Owen

  University of Arizona

  5 shared

• Jeremy Weiss

  University of Arizona

  4 shared

• Sarah LeRoy

  University of Arizona

  4 shared

Labs

• Heat Resilience InitiativePI

Education

• PhD in Arid Lands Resource Sciences, Graduate Interdisciplinary Degree Program

  University of Arizona

  2019

• M.S. in Planning, Planning Program

  University of Arizona

  2005

• B.A. in Media Arts, School of Media Arts

  University of Arizona

  2003