Summer no more arrives silently in the world’s warming cities. Across many global cities, intensifying heat, reflected in rising land surface temperature (LST), translates directly into rising hospital admissions, heat stroke deaths, and strained public services. Heat stress sits precisely at the intersection of a heating climate, swift and often unplanned urbanization, and irregular social vulnerability. The twelve contributions assembled in this Research Topic hint at the connection from satellite pixel to hospital bed, and from municipal ordinance to protective fabric. Collectively, they offer a unique, multi-scalar view of how heat becomes harm, and how that harm can be reduced.
Urban heat takes two related but distinct forms, LST and Air temperature (AirT). LST is the radiative skin temperature of the built and natural environment, captured by satellites. AirT is the ambient temperature bodies experience, and it underlies heat index and heat stroke risk. The two correlate positively, but LST responds more sharply to surface material than air temperature does. LST nonetheless serves as a valuable proxy for heat exposure where dense AirT networks are lacking. Urban heat begins, quite literally, with land itself. In Lahore, Pakistan, the built-up area expanded from 22.99% to 47.17% between 2000 and 2020, while vegetation cover shrank. This drove mean LST up by nearly two degrees, tightening the statistical bond between built-up density and surface heat (Shah et al.). A comparable, sharper story unfolds in Patna, India, where a 4.41%–12.34% surge in built-up area between 2017 and 2023 pushed LST into the highest-heated class (i.e., 49.677 °C). It also enlarged the very strong urban heat island (UHI) zone across the entire study area (Bharti and Roshni). These two case studies, unalike in scale but alike in message, show that land use/land cover (LULC) change is a primary engine of surface UHI intensification in swiftly growing South Asian cities. Detecting where this transformation is unfolding requires monitoring that keeps pace with it, rather than periodic snapshots. Meeting that need, a foundation-model GeoAI pipeline developed for Indianapolis, the United States of America (USA), assimilates Earth-observation and atmospheric models to generate hourly, high-resolution temperature fields. This shift moves heat surveillance from occasional snapshots toward continuous, decision-ready early warning (Johnson).
Heat matters as bodies absorb it unevenly. Experimental work in the laboratory, comparing young and adult rats under heat stress, finds that young rats tolerate heat better physiologically. This advantage is sustained by stronger intestinal barrier integrity and heat shock protein responses. Yet real-world pediatric heat stroke outcomes remain poor, because behavioral limits and caregiver lapses, especially in enclosed vehicles, override this biological advantage (Cai et al.). At the human population scale, climate projections for the Indian state of Uttar Pradesh show that heatwave frequency and heat index severity will increase abruptly by mid- and end of the century. This trend drives nearly every district toward unsafe thresholds, not only indicating but demanding localized adaptation now, not later (Awasthi et al.). The urban fabric itself also shapes vulnerability: a comparison of Sandton and Tembisa in Gauteng Province in South Africa, shows how vegetation health, air pollutants, and LST interact in a different way based on the degree of urbanization, with implications for who breathes cleaner, cooler air (Ngebe et al.). Translating these connections into actionable risk maps, a community-level assessment of Shijiazhuang in China finds that hazard peaks near the city center while vulnerability peaks at the periphery. This evidence shows that heat risk is not one problem but two, requiring different interventions in different places (Song et al.). The human cost of these intensifying pressures is made blatantly evident in Karachi, Pakistan, where rising heat stroke mortality between 2010 and 2024, worsened by simultaneous power crises that disable cooling infrastructure, is described as nothing short of a medical emergency (Saadat et al.).
If LULC creates heat and social structure distributes its harm, then adaptation must work on both fronts at once. Across forty one cities of the Yangtze River Delta in China, blue-green spaces evidently cool their surroundings, but their effectiveness is spatially uneven: fragmented green patches lower LST where water bodies are abundant, yet raise LST where water is scarce, meaning cooling strategies cannot simply be transplanted between regions (Li et al.). A machine learning analysis of Anhui Province of China similarly identifies built-up patch size and cropland coverage as dominant, quantifiable drivers of canopy heat island intensity, knowledge the authors then convert directly into a flipped classroom teaching model that trains future planners on the very data shaping their cities (Shi et al.). Physical redesign also needs institutional backing. An audit of shade policy across eight states of the USA, four in the southwest and four in the northeast, finds that three-quarters of municipalities regulate shade. Yet few frame that regulation explicitly as heat protection rather than aesthetics, revealing a gap between what is written and what actually protects (Buller et al.). Finally, for those who cannot wait for cooler cities, outdoor and emergency workers, controlled trials of rescue clothing in hot, humid chambers show measurable physiological and perceptual strain differences. These findings offer a practical, near-term tool for occupational heat safety (Qian et al.).
Read together, these twelve studies build a cumulative, evidence-based case rather than twelve isolated ones. Heat stress is produced by measurable, LULC-driven physical processes; it is distributed unevenly across age, geography, and infrastructure; and it can be addressed only through interventions that span satellite monitoring, urban design, education, policy, and personal protective equipment. Mitigation, reshaping land cover, water bodies, and building form, reduces the hazard at its source. Adaptation, risk mapping, shade policy, protective clothing, and early warning systems protect those already exposed while structural change unfolds. Neither is sufficient alone; a city that cools its center without protecting its periphery, or that maps risk without funding shade, will continue to lose lives to a threat that is, unlike many facing humanity, visible well in advance. We anticipate this Research Topic equips researchers, planners, and public health practitioners with both the diagnostic tools and the design principles needed to meet that threat before the next heatwave arrives.
Statements
Author contributions
MS: Writing – original draft. AS: Writing – review and editing. B-JH: Writing – review and editing.
Funding
The author(s) declared that financial support was not received for this work and/or its publication.
Conflict of interest
The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
The authors MS, AS, B-JH declared that they were an editorial board member of Frontiers at the time of submission. This had no impact on the peer review process and the final decision.
Generative AI statement
The author(s) declared that generative AI was used in the creation of this manuscript. AI was used to synthesize the text, drawing on the twelve articles published in this Research Topic. After using this tool, the author(s) reviewed and edited the content as needed and take(s) full responsibility for the content of the publication.
Any alternative text (alt text) provided alongside figures in this article has been generated by Frontiers with the support of artificial intelligence and reasonable efforts have been made to ensure accuracy, including review by the authors wherever possible. If you identify any issues, please contact us.
Publisher’s note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.
Summary
Keywords
climate adaptation, heat mitigation, heat stress, LULC, public health risk assessment, UHI
Citation
Sarif MO, Sharifi A and He B-J (2026) Editorial: Heat stress and public health issues: impacts, adaptation, and mitigation. Front. Environ. Sci. 14:1950495. doi: 10.3389/fenvs.2026.1950495
Received
28 July 2026
Accepted
28 July 2026
Published
05 August 2026
Volume
14 - 2026
Edited and reviewed by
Martin Siegert, University of Exeter, United Kingdom
Updates
Copyright
© 2026 Sarif, Sharifi and He.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Md. Omar Sarif, sarif@hiroshima-u.ac.jp
Disclaimer
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.