Assessing ethical aspects of heat adaptation in informal settlements in LMIC urban areas using a disaster justice informed theory: a rapid review

Introduction

Climate change has been declared a public health emergency (Romanello et al., 2022) due to its widespread health impacts. Urban areas face particularly high risks due to dense populations and climate-sensitive infrastructure (Araos et al., 2016). These risks are further exacerbated by socioeconomic inequalities and rapid urbanization (Schmidt, 2023). By 2050, approximately 70% of the global population is expected to live in cities (UN-Habitat, 2023). As a result, cities are becoming increasingly crucial in addressing climate change, as their susceptibility to climate and disaster risks intensifies with urban growth (Mukim and Roberts, 2023). Despite the urgency of the situation, only 10% of major urban areas worldwide report having public health adaptation initiatives in place (Araos et al., 2016).

• Urban heat is a growing public health issue, especially for those with pre-existing health conditions, low-income individuals, older people, young children, and those living in areas with little to no vegetation due to higher exposure, higher sensitivity, and constrained adaptive capacity (Corburn, 2009; Guardaro et al., 2020; Harlan et al., 2006). The impacts of urban heat islands are predicted to worsen due to human-induced global warming, which is expected to increase average temperatures and potentially decrease precipitation in cities (Leal Filho et al., 2018), with LMICs being at higher risk (Campbell-Lendrum and Corvalán, 2007; Corburn, 2009). Studies consistently show positive associations between heat and increased morbidity and mortality, with social vulnerability amplifying these risks (Green et al., 2019). Between 2000 and 2019 it is estimated that approximately 489,000 heat-related deaths occurred each year, with 45% of these in Asia and 36% in Europe (Zhao et al., 2021). Addressing urban heat is crucial, particularly in cities in LMICs, as they face higher heatwave exposure. By the 2030s, the poorest regions are projected to experience heatwave seasons twice as long as wealthier areas (Alizadeh et al., 2022).
• To counteract the impacts of heat in cities, urban heat adaptation is proposed as a critical response. It includes strategies that improve communities’ capability to handle and lessen the negative impacts of high temperatures in urban areas. This includes structural strategies like cooling systems and green spaces to reduce local temperatures, as well as social strategies focusing on behavior, such as staying indoors during heatwaves or utilizing available support during emergencies (Leal Filho et al., 2018). It is especially important for vulnerable groups to be at the forefront of such interventions due to their higher susceptibility and fewer resources to recover, thereby maintaining a vicious cycle of deepening inequality (Islam and Winkel, 2017). Including the voices of communities in decision-making processes is essential for creating effective urban heat adaptation strategies that truly address their needs (Swanson, 2021). Despite this, existing research shows that representation and ethical concerns in urban heat adaptation are often overlooked, leading to inequitable outcomes.
• Slums and informal settlements are complex urban phenomena characterized by inadequate housing, limited infrastructure, and insecure land tenure (Dovey and Kamalipour, 2018; Mohanty, 2019). While these terms are often used interchangeably, they have distinct definitions. The UN defines slums as areas lacking basic services and adequate living conditions, whereas informal settlements develop without official authorization. According to UN-Habitat (2018) (p. V), “informal settlements are urban neighborhoods that developed outside the formal system recording land ownership, land tenure, and a range of regulations relating to planning and land use, built structures, and health and safety.” Slum households are defined as those in which inhabitants suffer from one or more of the following: lack of access to safe water sources, lack of access to sanitation facilities, lack of sufficient living area, lack of housing durability, and lack of security of tenure (UN-Habitat, 2003). Like other reports and articles (Borg et al., 2021; UN-Habitat, 2018), we also treat these terms interchangeably, as there is significant overlap between them. We use these terms to refer to settlements characterized by at least one of the features included in the definitions.
• Informal settlements, housing approximately 1 billion people in low- and middle-income countries, are especially susceptible due to poor-quality housing, lack of basic services, and often dangerous locations (Satterthwaite et al., 2020; UN-Habitat, 2003). These conditions significantly increase residents’ exposure to heat stress, especially in the absence of cooling infrastructure such as green spaces or ventilation (Satterthwaite et al., 2020). Additionally, informal settlements are often excluded from formal urban planning processes, resulting in limited representation in climate adaptation initiatives. This exclusion not only deepens existing inequalities but also undermines the effectiveness of resilience strategies. Addressing urban heat in these areas is therefore both a public health imperative and a matter of climate justice, requiring inclusive planning approaches that prioritize the needs of the most vulnerable (Anguelovski et al., 2016).
• It has been highlighted that adaptation strategies need to focus on distributive, procedural, and recognition justice to be effective and fair (Swanson, 2021). The lack of fair representation in urban heat adaptation often comes from the tension between needing quick solutions and the time-consuming effort to ensure justice. Inclusive planning, while fair, can lead to vague strategies that are hard to implement, whereas more focused plans tend to rely on strategic partnerships with key government or private actors, which often excludes marginalized communities to ensure smoother implementation and long-term stability (Swanson, 2021). Research also points out that adaptation plans tend to focus more on environmental and economic goals rather than addressing the social vulnerabilities of disadvantaged groups (Swanson, 2021). Most current heat adaptation strategies and studies mainly focus on cases from the Global North, which means there’s a significant lack of representation for vulnerable populations in LMICs and other global south contexts, despite these regions, particulalry LMICs in tropical and arid areas, often experiencing higher heat exposure and adaptive constraints (World Bank, 2025). With this review we aim to assess and scope out the current state of knowledge and identify the ethical aspects regarding representation of vulnerable groups in urban heat adaptation in LMIC.

Disaster Justice Theory emerges as a highly relevant framework for heat adaptation, focusing on equitable representation, fair participation, and resource distribution designed to address the unique needs of LMIC urban contexts. Disaster Justice examines how disasters disproportionately affect different groups, emphasizing the need to understand and address inequities in disaster preparedness, response, and recovery. Central to this theory are procedural justice, which ensures fair participation in decision-making processes, and distributive justice, which focuses on equitable allocation of resources and responsibilities (Lukasiewicz, 2020).

Building on these principles, this review draws from the PAC (Platform–Agent–Conviction) framework, as outlined in the context of disaster justice in Nepal’s earthquake recovery (Shrestha et al., 2019). This framework provides a structured approach to assess and address justice-related issues by focusing on three domains: accountability, representation, and recognition of diverse knowledge systems (Figure 1). The PAC framework emphasizes the need for specific structures, actors, and values that can actively challenge power imbalances and drive transformative change in disaster governance. Platform refers to inclusive spaces where diverse forms of knowledge such as scientific, local, and indigenous are acknowledged and integrated. Agents are individuals or groups who work to promote justice by navigating power dynamics and advocating for marginalized voices. Whereas conviction is their commitment to prioritizing the needs of the most disadvantaged.

Essentially, the PAC framework is a practical and analytical tool used to address injustices that often arise during disaster recovery, with a particular focus on the three interconnected domains of accountability, representation, and recognition of diverse knowledge systems. Each domain reflects the three PAC (Platform, Agents, Conviction) elements. For example, accountability may require platforms that ensure transparency, agents who demand answers, and a conviction to hold power to account. By approaching these domains holistically, the PAC framework helps identify where structures, actors, and values can align to challenge injustice and support more just outcomes in disaster recovery.

The elements of accountability, representation, and knowledge identified by Shrestha et al. (2019) share conceptual similarities with the three interconnected dimensions of distributive, procedural, and recognition justice as synthesized by Swanson (2021) from climate justice literature. Accountability corresponds to distributive justice through its emphasis on the “redistribution of resources” (Shrestha et al., 2019, p. 209) and the fair “allocation of benefits and burdens among multiple stakeholders” (Swanson, 2021, p. 291). Representation aligns with procedural justice as both emphasize the inclusion of different voices in participatory decision making through “inclusive decision-making” and addressing the “power and participation disadvantages” of marginalized groups (Swanson, 2021, p. 291). Finally, knowledge corresponds to recognition justice. While Shrestha et al. (2019, p. 209) emphasize the “recognition of multiple forms of knowledge,” Swanson (2021, pp. 288) defines recognition justice as making marginalized populations and their “needs and priorities” visible in policy development. Swanson’s synthesis further highlights the importance of local and community knowledge for effective adaptation.

In this context, PAC can be considered as an operationalized extension of the justice principles as outlined above. However, Shrestha et al. argue that for effective implementation especially in highly unequal local context like Nepal, the three interrelated PAC elements need to be in place.

Rapid review objective and question

• This rapid review aims to identify the current state of knowledge about ethical considerations of how at-risk groups are involved in urban heat adaptation in LMIC. It addresses the following question:
• What ethical aspects regarding participation of at-risk groups in heat adaptation have been identified for urban areas, particularly informal settlements, in low- and middle-income countries (LMIC)?

Methods

A rapid review is a form of evidence synthesis that gathers and summarizes findings from various research studies to create evidence for groups like the public, healthcare providers, researchers, policymakers, and funders in an efficient, systematic way. It achieves this by accelerating the processes involved in planning, conducting, and sharing the results of traditional structured (systematic) reviews, often by simplifying or excluding certain methods, which should be clearly outlined by the authors (Garritty et al., 2024). Our process adhered to the updated Cochrane rapid review recommendations (Garritty et al., 2021), see Table 1. Table 2 lists the PICO criteria that guides the selection and inclusion of the studies.

Table 1. Overview of key points.

Table 2. PICO.

We adopted the terminology developed by UN-Habitat for informal settlements. This review followed the PRISMA 2020 guidelines (Page et al., 2021), with the completed checklist provided in Supplementary File 1. To ensure transparency, a rapid review protocol was preregistered on the Open Science Framework (OSF) and is available at: 10.17605/OSF.IO/SHKE2.

Search strategy

An initial literature search was done using key terms to cover various thematic areas:

• Terms related to extreme heat: heat, extreme heat, heat wave, heatwave
• Terms related to adaptation: adaptation, preparedness, ‘action plan’, management, ‘hazard mitigation’, resilience
• Terms related to informal settlements: slum, settlement
• Terms related to low and middle-income countries (LMICs): Low and middle income countr, LMIC, developing countr, Global South, emerging econom, low income region, middle income region

The search strings for each database are provided in Supplementary File 2 (Table 2).

During piloting a search using the term “ethics” was additionally run but yielded zero relevant results. The literature seems to not explicitly use the term “ethics” in the context of informal settlements and heat research, to date. However, ethical considerations remain central to our review and are addressed through a broader analytical lens with a stronger focus on concepts of justice. Drawing on the PAC framework, our analysis addresses ethics by examining both the three core domains of disaster justice - representation, recognition, and accountability, including the actors, structures and actions emphasized by PAC to enhance disaster justice, challenge power imbalances and enable transformative change in disaster governance. Rather than relying on explicit mentions of “ethics,” our approach identifies relevant themes through the lens of this framework. Ethical concerns were expected to surface in how interventions are prioritized, whose needs are recognized, and how community voices are included, or excluded, in decision-making. Our screening and synthesis process therefore incorporated an analytical step to identify these dimensions, whether implicit or explicit. Supplementary File 2 (Table 1) outlines the definitions of the PAC components, as well as the adapted guiding questions we developed to support data extraction.

Data management and study selection process

Screening was conducted using the online review management software Rayyan (Rayyan Systems Inc., Cambridge, MA, United States. Available at www.rayyan.ai). Inclusion of studies was determined in two stages: stage 1, titles and/or abstracts; stage 2, full text. Abstract and full-text screening were conducted independently by five reviewers (LR, JL, FK, TA, DB), with each study assessed by two reviewers. Discrepancies were resolved through discussion among all reviewers. Additional relevant publications were identified and included through a review of the reference lists, using a snowballing approach (OA, JL). The identified studies through snowballing, came primarily from Tavares et al. (2024)’s systematic review. To prevent duplication in the dataset, Tavares et al. (2024) was not included in the analysis. Other literature or systematic reviews were included in our analysis as suggested by Garritty et al. (2021).

The studies that did not meet the inclusion criteria during the full-text review were excluded, and a list of all excluded studies was kept. To maintain the scope and relevance of the review, studies that did not address any of the PAC components were also excluded.

Data extraction

Data extraction adhered to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for transparency and consistency. A standardized data extraction form was used to record key details, including bibliographic information (author, year), study objectives, climate exposure, country and city, outcome measures, and study design. It also captured main findings, urban heat adaptation or mitigation measures, and ethical considerations based on the PAC framework as outlined above. LR, JL, KF, DB, TA, FK and OB independently performed the extraction using the standardized data extraction form.

Data analysis

We assessed contents using the theoretical framework based on the PAC framework. A thematic content analysis approach guided by Clarke and Braun’s (Clarke and Braun, 2017) steps was used to analyze how the texts address the framework’s aspects of representation, accountability, recognition, agents of change, platform and conviction. Analysis was conducted by LR, KF and JL.

Results

A total of 227 citations were screened based on the inclusion and exclusion criteria, resulting in the inclusion of 30 relevant studies for the final review. The study designs of the included studies were heterogenous. Out of all the included studies, five were observational studies (Akbari and Sharifi, 2024; Ehsan et al., 2021; Mahadevia et al., 2020; Ramsay et al., 2021; Van de Walle et al., 2022), four were reviews (Borg et al., 2021; Chaudhry, 2024; Lemaire, 2021; Reckien et al., 2016), four were mixed-methods studies (Handayani et al., 2024; Huq and Shafique, 2023; Knowlton et al., 2014; Pasquini et al., 2020), two were case studies (Rana et al., 2022; Yi et al., 2022), eight were cross-sectional studies (Rathi et al., 2022; Swain et al., 2019; Tran et al., 2013; Vellingiri et al., 2020; Cavan et al., 2014; Hossain et al., 2022; Wang et al., 2019; Muñoz-Pizza et al., 2023), two were quantitative empirical studies (Nutkiewicz et al., 2022; Ramsay et al., 2023), one used a survey study design (Adegun et al., 2022), one was a qualitative empirical study (Wilk et al., 2018) and one study did qualitative ethnographic fieldwork (Salsabila et al., 2023). Finally, Harish et al. (2020) employed an observational study using econometric panel data methods, and Wilby et al. (2021) conducted anobservational field study. The studies were published between 2013 and 2024 and were conducted across different countries in the global south, such as Pakistan, India, Uganda, Ghana, Tanzania, Afghanistan, Indonesia, Bangladesh, Ethiopia, South Africa, Ecuador, Mexico, Brazil, Kenya and China. Figure 2 presents the inclusion process as depicted in the PRISMA flow diagram. Table 3 presents an overview of the inclusion of the PAC components within the included studies. The extraction sheet containing data extracted from each study in relation to the PAC components is also available as Supplementary material (Supplementary File 3).

Table 3. Overview of PAC framework components identified across included studies.

Accountability

Most of the included studies (22/30) do not address mechanisms of accountability or an equitable climate adaptation resource distribution. The studies that do address this component indicate a limited or entirely absent equitable distribution of resources for heat adaptation. For example, Lemaire (2021) highlights deficiencies in the official implementation of urban planning measures in response to climate change, resulting in communities within informal settlements taking adaptation efforts into their own hands. Similarly, Mahadevia et al. (2020) point to an absence of official, long-term programs aimed at improving housing and living conditions in informal settlements as part of a broader climate adaptation strategy. Knowlton et al. (2014) argue that extreme heat represents a poorly acknowledged public health threat that is insufficiently addressed through current management strategies. Pasquini et al., 2020 note that in some cases, heat health action plans are not in place, and health sector respondents lack comprehensive knowledge of the impacts of heat on human health. According to Muñoz-Pizza et al. (2023), current adaptation strategies are overly unspecific in terms of measures and resource allocation. Furthermore, they are outdated, inadequately executed, with climate change yet to be incorporated into urban plans. While Wilk et al. (2018) note that existing policies for disaster management are often poorly implemented or enforced.

Accountability mechanisms are scarcely addressed in the reviewed literature. Reckien et al. (2016) explicitly notes a prevailing lack of accountability in climate adaptation governance. However, Huq and Shafique (2023) report a collaborative effort between community leaders and legal advocates aimed at contesting policy decisions regarding eviction and resettlement conditions.

Representation

Representation is addressed by a substantial portion of included studies (9 out of 30). However, these studies primarily focus on the special considerations that minority or vulnerable groups have in dealing with heat, rather than including these groups in heat adaptation processes. A few studies specifically address the situation of women in this context (Rana et al., 2022; Reckien et al., 2016; Lemaire, 2021). These studies focus on the gendered and unequal impacts of climate change, showing that women, especially in marginalized or informal contexts, are particularly vulnerable due to social roles, norms, and systemic inequalities. They emphasize the need for inclusive, gender-sensitive, and intersectional approaches in adaptation planning and research while highlighting challenges in participatory processes that may exclude or overlook marginalized voices. A scoping review by Borg et al. (2021) provides recommendations to strengthen communities through local participation in decision-making and communication. Strengthening participatory and transparent urban governance is also seen as essential to safeguarding vulnerable groups, especially in informal settlements by Chaudhry (2024). Adegun et al. (2022) emphasize the need for public health measures to be factored into heat action plans and for individual, behavioral, and sociocultural differences between groups to be considered. For instance, they argue that women may respond differently to heat due to the cultural norms regarding clothing.

Two studies carried out needs and vulnerability assessments to identify at-risk groups and their susceptibilities. Knowlton et al. (2014) found a higher prevalence of heat-related illnesses among slum dwellers, a scarcity of protective measures among them, and particularly vulnerable groups being outdoor workers and infants. Based on this, they developed four policy papers aimed at raising awareness about the risk of urban health and provided recommendations for government officials, among others. Muñoz-Pizza et al. (2023) conducted a vulnerability assessment, with special consideration for children and seniors, due to their greater physiological susceptibility. They suggest community-based adaptation that considers the underlying causes of vulnerability and equipping vulnerable groups with individual coping strategies to tackle the impacts of heat-related health issues. Apart from these suggestions and recommendations, the studies do not demonstrate systematic inclusion of marginalized groups in decision-making processes. On the other hand, Wilk et al. (2018) specifically report a lack of inclusion of vulnerable groups in decision-making, rather than only in the implementation of proposed actions.

Knowledge

Most of the studies (23/30) fail to address the recognition and integration of different ways of knowing, especially from marginalized communities. Despite this gap in research, our findings show that local and culturally rooted knowledge is often present and relied upon by residents in informal settlements, e.g., vernacular cooling practices. Swain et al. (2019) for example mention the use of straw to cover rooftops or methods involving the use of water such as drinking and spraying as common cooling practices in informal settlements. Rana et al. (2022) similarly report practices such as hanging wet sheets, wearing loose clothing and covering the head during heat exposure. In formal adaptation planning this knowledge is still rarely recognized. Lemaire (2021) emphasizes the importance of integrating local knowledge, as community members can provide valuable insights into their environment, which can support effective climate adaptation and enhance resilience. Furthermore, local beliefs and skepticism can influence the acceptance of adaptation strategies and should be considered during planning (Wilby et al., 2021). Adegun et al. (2022) also note that sociocultural norms, such as purdah system, directly affect how women can respond to heat.

According to Huq and Shafique (2023), justice-oriented adaptation must recognize local knowledge and grassroots resilience practices. Participatory processes such as multi-stakeholder dialogs are essential in the development of adaptation measures and particularly successful if vernacular knowledge is recognized and included (Wilk et al., 2018). However, marginalized perspectives and community-derived strategies remain undervalued and largely excluded in decision-making spaces (Huq and Shafique, 2023; Lemaire, 2021; Wilk et al., 2018).

Platform

Most studies (24/30) do not address an inclusive forum for participatory deliberation. However, some studies highlight the importance of establishing platforms that enable multiple stakeholders to engage in dialog, facilitate knowledge exchange, and support collaborative decision-making. Swain et al. (2019), for instance, underscore the necessity of adopting a multilevel approach to policymaking. Similarly, Lemaire (2021) identifies public platforms as a relevant strategy for including residents of informal settlements in participatory planning and management processes aimed at sustainable climate adaptation. Handayani et al. (2024) argue that local communities should be advised on how building design decisions and construction or renovation practices can contribute to heat adaptation. To that end, facilitating an exchange of knowledge between experts and local communities would be beneficial. These studies collectively point to a lack of shared spaces where diverse stakeholders, including informal settlers, can meaningfully collaborate.

Knowlton et al. (2014) engaged various international and local stakeholders, including members of vulnerable communities, in the development and implementation of a heat-health action plan. They facilitated collaboration among diverse partners, established local coalitions and conducted public outreach to strengthen multi-stakeholder engagement. Wilk et al. (2018) report in their study that while community representatives were included in the implementation of action plans, they did not participate in planning and decision-making processes. Huq and Shafique (2023) report on a successfully implemented platform mechanism in practice, which specifically addresses housing justice for communities affected by climate impacts.

Agents of change

Most studies (21/30) do not address decision-makers or stakeholders advocating for vulnerable and marginalized groups. Among the few that do, “agents of change” are typically consulted or engaged in implementation rather than actively advocating for marginalized communities.

For instance, several studies highlight the role of diverse actors as agents of change in promoting the inclusion of marginalized groups and ensuring fair access to heat adaptation resources. Rana et al. (2022) recommend that government integrates tools like the LCZ (local climate zones) concept into planning and stress collective greening responsibilities. Reckien et al. (2016) underscores the importance of economic incentives and the central role of women in adaptation efforts as “key agents of change” (p.20). Wilby et al. (2021) emphasize the involvement of “community champions” – local residents liaising between researchers and community. Lemaire (2021) discusses the need for institutional brokers to connect with the voiceless and value vernacular knowledge. Handayani et al. (2024) stress the importance of empowering residents and construction workers with technical knowledge through expert support. Huq and Shafique (2023) describe collaboration between community leaders, NGOs, and legal advocates challenging evictions and shaping adaptation policy. On the other hand, Nutkiewicz et al. (2022) note that global governments and NGOs work to improve informal settlements, but redevelopment strategies can inadvertently harm vulnerable populations, illustrating the dual role of these actors as both change agents and potential contributors to inequity. Wilk et al. (2018) frames advocacy for inclusiveness, procedural representation, and justice in urban climate adaptation as aspirational, highlighting the potential for marginalized groups to act as active agents of change rather than passive recipients. Knowlton et al. (2014) conducted a needs assessment which found higher susceptibility to heat among urban settlers and identified most at-risk groups, such as infants, and devised four policy papers and recommendations regarding these risks for healthcare providers, slum inhabitants, outdoor workers, and government officials. This demonstrated the efforts of researchers to advocate for at risk groups by conducting research and devising policy papers.

Conviction

Our findings indicate a strong ethical conviction across the literature to prioritize the needs and perspectives of residents in informal settlements, with the majority (27/30) of the included studies reflecting this by highlighting existing vulnerabilities, addressing structural inequalities and calling for targeted heat adaptation measures. The included studies support a paradigm shift in climate adaptation toward prioritizing the most vulnerable, especially residents of informal settlements. Rana et al. (2022) highlight the precarious situation of residents in informal settlements due to the lack of cooling systems (air conditioning, shaded green spaces, water coolers) and the dominance of main outdoor daytime employment, which exposes them to a greater risk of heat illness. To effectively reduce health-related heat risks, Swain et al. (2019) call for policy actions across various levels of governance including awareness programs that address chronic illnesses and promote coping strategies for heat-related illness. Knowlton et al. (2014) see potential in the training of health care workers to address heat-related illness by identifying health risks, delivering heath education and supporting local surveillance in vulnerable communities. Tran et al. (2013) underscore similar approaches and additionally call for targeted measures for older adults and individuals working in non-shaded areas. They also highlight the importance of constant access to piped water in informal settlements to prevent dehydration and enable cooling practices, and the implementation of heat illness surveillance systems. Harish et al. (2020) and Nutkiewicz et al. (2022) argue that access to affordable electricity for cooling during extreme heat is an important adaptation measure for vulnerable populations. Several of our included studies highlight that informal settlements are structurally disadvantaged and thus particularly vulnerable to urban heat. For example, in Dhaka, slums consist of overcrowded, single-story houses with minimal open space or vegetation, creating conditions that elevate surface temperatures in comparison to larger, lower-density areas (Hossain et al., 2022). Lemaire (2021) suggests that access to low-cost insulating materials should be improved and that simplified building standards targeting informal settlements could help residents enhance their housing structures and improve thermal comfort. Similarly, Akbari and Sharifi (2024) recommend strategies such as expanding urban greenery, increasing shading and using reflective building materials as well as light-color paintings. Salsabila et al. (2023) propose low-cost, community-based cooling strategies, such as transforming shared outdoor spaces into shaded, socially used areas that also allow for airflow, that can be implemented even in dense informal settlements with limited space and financial resources.

Discussion

In this review, we synthesized peer-reviewed literature on urban heat adaptation in informal settlements in LMICs. Furthermore, we adapted the PAC framework by Shrestha et al. (2019) to analyze ethical considerations in urban heat adaptation. For this purpose, we examined six domains of disaster justice: accountability, representation, knowledge, platform, agents of change, and conviction.

The included studies reveal gaps across all six components of the PAC framework.

The reviewed studies point to a lack of accountability mechanisms in heat adaptation governance, with limited or absent mechanisms to ensure fair and transparent distribution of heat adaptation resources or hold decision-makers responsible. Representation remains limited as the studies highlight the limited inclusion of marginalized groups, especially women, in climate adaptation decision-making, despite recognition of their heightened vulnerability. Knowledge integration is insufficient: although residents of informal settlements often draw on local and culturally rooted knowledge and practices to adapt to heat, this type of knowledge is rarely considered in official contexts, with only a few included studies calling for meaningful integration in these contexts. Platforms enabling participatory dialog and shared decision-making are scarce, although some cases document collaborative structures for heat-health action planning. Agents of Change appear in the form of researchers, women, brokers, and experts who advocate for marginalized groups or facilitate knowledge exchange, yet such advocacy is neither widespread nor structurally embedded. Finally, most of the included studies demonstrate a clear ethical conviction that recognizes vulnerabilities and prioritizes the needs of residents of informal settlements. The studies also address structural inequalities and provide suggestions for an equitable distribution of heat adaptation resources.

Our review reveals patterns of exclusion and inequity that affirm the core concern of disaster justice theory: disasters disproportionately burden the least powerful, whose social and economic marginalization heightens their exposure, susceptibility, and reduces their capacity to cope (Shrestha et al., 2019). The Nuffield Council on Bioethics (2023) underscores the need for justice-oriented processes to address climate-related health inequities. Like Shrestha et al. (2019), they advocate for both procedural justice, through inclusive and transparent decision-making processes, and distributive justice requiring the equitable allocation of both the benefits of adaptation and the burdens of climate change. The prevalent lack of accountability mechanisms (Lemaire, 2021; Reckien et al., 2016), the limited inclusion of marginalized groups in decision-making (Wilk et al., 2018), the scarcity of established participatory platforms (Lemaire, 2021; Swain et al., 2019) and the under-valuation of local knowledge (Wilk et al., 2018; Lemaire, 2021), despite the recognition of their vulnerability, demonstrate a clear procedural justice deficit.

Furthermore, the Nuffield Council on Bioethics (2023) stresses that policymakers must conduct a rigorous assessment of trade-offs to avoid solutions that create new, intensified burdens for others. They illustrate this with the example of air conditioning, which reduces heat exposure for some while creating urban heat islands and being unaffordable for low-income groups. The existence of these unfair trade-offs is supported by our findings, showing that adaptation strategies are often poorly implemented and fail to address the root causes of vulnerability (Muñoz-Pizza et al., 2023), indicating a deficit in distributive justice. Beyond the balancing of outcomes, the Council underscores the fundamental consideration of respecting human rights, arguing that a policy is unethical despite maximizing overall benefits if those harms fall disproportionately on already disadvantaged population.

Drawing on intersectionality, such harms cannot be understood through single categories like gender alone, since for instance women’s experiences are shaped by overlapping inequalities such as class, race, migration status, and other forms of marginalization (Crenshaw, 1991). Similarly, feminist environmentalism highlights that although women are disproportionately affected by environmental degradation because of their gendered responsibilities and socioeconomic position, they possess valuable knowledge and capacities as environmental stewards and change agents (Agarwal, 1992). However, in line with MacGregor et al. (2022), greater attention should also be paid to the barriers women face as change agents and to the risk of relying on their unpaid care and environmental work without adequate recognition, redistribution, or state support. Future research and adaptation projects should thus adopt intersectional and care-sensitive approaches that address the compounded vulnerabilities of women in informal settlements while ensuring that marginalized voices are meaningfully included in participatory processes.

The Council furthermore emphasizes the need for inclusivity, transparency and cultural sensitivity. They argue for a meaningful involvement of affected communities and the need for intercultural discourse to share knowledge. The Council frames this primarily as an ethical consideration for research, which corroborates our findings, as we found that local and vernacular knowledge was frequently documented in studies of community practices (Swain et al., 2019; Rana et al., 2022) but was rarely recognized or integrated into formal adaptation planning (Lemaire, 2021; Wilk et al., 2018; Huq and Shafique, 2023). We therefore advocate for the formal integration of justice-based frameworks, like the PAC framework, into urban adaptation planning to promote equitable actions that prioritize the most vulnerable and ensure their meaningful inclusion in decision-making.

Limitation

Data extraction was challenging and may be prone to researcher bias and subjectivity, as the inclusion of PAC components or ethical considerations were often not explicitly reported in the included studies, which may impact the consistency and interpretation of the findings. This difficulty was compounded by the fact that the included papers were not primarily focused on the ethical dimensions of heat adaptation. In several cases, studies only partially addressed PAC components; however, these were still included and noted in the results section. Additionally, the study designs were highly heterogeneous, ranging from qualitative interviews to modeling studies, where the extent to which ethical aspects were incorporated varied considerably. For example, in some studies the ethical considerations appeared aspirational or suggestive, whereas in others they were embedded as part of an intervention. However, we aimed to keep the inclusion criteria broader and include also the studies that solely suggest ethical considerations to be included in future interventions or research. This way, we could also ensure that the review reflected the diversity of the evidence and avoided excluding studies that, despite limited empirical depth on ethical issues, nonetheless contribute important insights into how ethical considerations might be operationalized in future interventions.

Additionally, several methodological limitations that may affect the conclusions of the review. First, the restriction to English-language literature may have introduced language bias, potentially excluding relevant studies published in other languages, particularly those originating from LMICs. Second, the exclusion of gray literature, such as reports and publications produced by NGOs and international bodies, may have resulted in the omission of valuable evidence.

Third, the search strategy was limited to selected databases and predefined search terms, which may have resulted in the exclusion of relevant studies that were not indexed in the searched databases or that used different terminology to describe climate adaptation, ethics, or informal settlements. Furthermore, the findings may not be universally applicable across all informal settlement contexts, as ethical considerations and governance conditions are shaped by local social, political, and institutional factors. Finally, given the diversity of study designs and the review’s aim to provide a broad overview of the evidence, a formal quality appraisal was not undertaken.

To our knowledge, this is the first review that systematically examines the ethical aspects of heat adaptation using the PAC framework. By applying PAC as an analytical lens, our study highlights how ethical principles are currently addressed, where they are missing, and where further guidance is needed based on existing research and practice. The emphasis on informal settlers in LMICs through the lens of PAC framework is particularly important as it situates justice within disaster contexts where risk exposure and response capacities are highly unequal. The findings shed light on the inconsistency and limited or lack of integration of ethical considerations, which reflects the broader absence of established ethical frameworks guiding heat adaptation research and practice. Hence, future efforts should focus on developing structured, operational tools that help consistently integrate ethical principles into research or interventions. Future research could also explore how responsibilities for heat adaptation are assigned, monitored, and enforced across government levels. In addition, future studies should explicitly report how ethical elements were considered in design, implementation, and evaluation. In practice, future climate adaptation projects should include include governance conditions that ensure transparency and accountability. This includes publicly documenting responsibilities and decisions, enabling independent review, and regularly reporting outcomes across governance levels. It should also include structured ways to collect and integrate local knowledge through participatory platforms. These measures are particularly important in informal settlement contexts, where constrained participation in formal decision-making and the persistent labeling of settlements as “illegal” can limit access to institutional support and reduce investment in climate adaptation. This highlights the importance of justice-oriented governance approaches that acknowledge informal settlement residents as legitimate urban citizens and essential contributors to resilience-building processes (Dlamini and Ncube, 2026).

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Supplementary material

The Supplementary material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fclim.2026.1873994/full#supplementary-material

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Footnotes

Edited by: Omar Hamdy, Aswan University, Egypt

Reviewed by: Yosef Prihanto, National Research and Innovation Agency (BRIN), Indonesia

Fredua Agyemang, North-West University, South Africa

Emal Ahmad Hussainzad, Wuhan University, China

Maria Belen Lopez, National University of General San Martín, Argentina