Finding the right target: Personalizing treatment for an aggressive asbestos-linked cancer

A new clinical trial, led by researchers in Leicester, is investigating a new personalised treatment for patients with a rare and aggressive form of cancer, potentially giving them more time with their loved ones

University of Leicester

Facebook

XLinkedInWeChatBluesky
Email

 

image: 

Professor Dean Fennell

view more 

Credit: University of Leicester

A new clinical trial, led by researchers in Leicester, is investigating a new personalised treatment for patients with a rare and aggressive form of cancer, potentially giving them more time with their loved ones.

 

Mesothelioma is a cancer that forms in the lining of the lungs or abdomen and is linked to exposure to dangerous asbestos fibres. Around 2,700 people are diagnosed with the disease each year*, but outcomes and survival rates are poor.

SELECTmeso1 is a new trial, investigating whether a targeted cancer treatment can improve outcomes for patients who have a particular genetic biomarker.

 

The trial is led by Professor Dean Fennell and Professor Gareth Griffiths from the Leicester and Southampton NIHR Biomedical Research Centres (BRC) respectively and run by the Cancer Research UK Southampton Clinical Trials Unit, with funding from Asthma + Lung UK.

 

Tailoring treatments

There are currently very few treatment options for people with mesothelioma, and often the cancer will return after initial treatment.

In fact, only around five per cent of people diagnosed with the disease will survive for five years or more.

 

Recent clinical trials in mesothelioma conducted by the NIHR BRC Leicester and the Southampton Clinical Trials Unit** have shown that targeted treatments can improve survival for people with relapsed mesothelioma, where the disease has come back.

However, these treatments often only work for some patients but not for others.

“This is due to the genetic make-up of people’s individual cancer and the specific biomarkers, or genetic signals, their cancer has,” says Professor Fennell, Chair of Thoracic Medical Oncology at the University of Leicester and Chief Investigator of SELECTmeso1.

 

“But imagine if there was a way to tell which treatment is likely to work best for each patient and personalise the care they get, giving them best chance of a successful outcome.

 

“The SELECTmeso1 trial is doing just that. We know that almost half of patients with mesothelioma have a deletion of a particular gene called MTAP which means they have a more aggressive cancer and don't respond as well to existing treatments.

 

However, the absence of this gene creates a unique weak point in their cancer cells that healthy cells don't have, meaning the cancer cells are able to grow, uncontrolled. This is the genetic pathway we are targeting in this trial.”

 

The team are working with pharmaceutical company Bristol Myers Squibb, which has developed a drug called Navlimetostat*** which targets the weak point created by the absence of the MTAP gene and selectively kills those cancer cells, leaving the healthy cells largely unaffected.

 

“This drug has already been trialled in some other cancers and has been shown to have promising anti-tumour activity,” says Professor Gareth Griffiths, Director of the Southampton Clinical Trials Unit and co-Chief Investigator.

 

“It was also well tolerated by patients without causing too many side effects. Through the SELECTmeso1 trial, we therefore hope to find out whether this could be a viable treatment for patients with this specific genetic signal. If we find evidence that patients benefit, this will hopefully lead to future practice-changing trials.”

 

Patients with relapsed mesothelioma who are found to have the deleted MTAP gene will be invited to join the SELECTmeso1 trial. They will be given the targeted treatment in the form of tablets every day, in three-weekly cycles, for up to six months, and the research team will monitor how much their tumour shrinks as well as any side effects they experience.

 

The trial has recently opened at Leicester Royal Infirmary where the first patients have been recruited and is due to open at 10 hospitals across the UK, recruiting 30 patients.

 

Dr Samantha Walker, Director of Research and Innovation at Asthma + Lung UK, said: “Asthma + Lung UK is proud to be funding this vital research, which could be a real breakthrough and has the potential to improve the lives of people living with mesothelioma. With life expectancy remaining low and no current cure available, progress on treating this devastating condition is desperately needed.

 

“Targeted therapy has already shown to be effective for other types of cancer. If this trial is successful, it would offer new hope for the more than 2,000 people who are diagnosed with mesothelioma every year****. Cutting edge research into new types of treatment for lung conditions is vital to improve health outcomes but funding for lung health research is currently on life-support, despite lung conditions remaining the third biggest cause of death in the UK.”  

 

It is the first trial supported by the newly formed UK collaborative for clinical cancer research (UK3CR’s) Mesothelioma Clinical Research Group chaired by Professor Fennell, which has the remit to develop trials for mesothelioma patients in the UK.     

 

Looking for more targets

SELECTmeso1 is the first trial in a much larger planned platform clinical trial. This aims to test several targeted drugs which work against different genetic biomarkers that may be present in a patient’s mesothelioma.

 

“The idea of the platform trial is that we can run several different trials at once, giving patients more chance of receiving a treatment that works for them,” says Dr Emma Knox, Senior Trial Manager for SELECTmeso at the Southampton Clinical Trials Unit.

 

“Once the full platform is open, patients will be invited to join and will have a sample of their cancer tested in a laboratory. This will tell doctors about the particular genetic make-up of their cancer and what biomarkers their mesothelioma has. If there is a trial within the platform that is testing a drug that works specifically for that biomarker, they will be invited to join that particular trial.”

 

If there is no trial running for that biomarker at that time, patients will remain in the platform database and will be contacted if a new trial of a treatment that may work for them comes on board.

 

Each separate trial within the SELECTmeso platform will recruit 26-30 patients, and the trials will take place at hospitals around the UK.

 

“The aim of the platform is to test how effective each drug is for patients with those specific biomarkers and to see whether stratifying treatment in this way can improve outcomes for patients,” continues Professor Fennell.

 

“The hope is that in the future, doctors treating people with this aggressive cancer will be able to use a more personalised approach, selecting the best possible treatment for each individual patient.”

 

SELECTmeso1 is run by the Southampton Clinical Trials Unit and Professor Dean Fennell at the University of Leicester. It is funded by Asthma + Lung UK with Bristol Myers Squibb who are providing the drug for the trial and is sponsored by University of Southampton.

 

*Figures from Cancer Research UK

**The MiST, CONFIRM and NERO trials.

*** Navlimetostat, also known as BMS-986504, is a first-in-class, MTA-cooperative PRMT5 inhibitor developed by Bristol Myers Squibb.

**** Mesothelioma, NHS England, September 2022

 

Ends

 

For media enquiries and interview requests, please contact:

 

Joanna Jones, Science Communications Manager, NIHR Leicester BRC  on 07966 678057 or email Joanna.x.jones@uhl-tr.nhs.uk

 

 

 

 

 Notes to editors

 

 

About the University of Leicester  

The University of Leicester is a leading global university, home to more than 21,000 students and 4,000 staff, with an outstanding reputation for world‑class research, innovative teaching and widening access to higher education.  It holds an overall Gold rating in TEF 2023 and is ranked among the UK’s Top 30 for research quality, with 89% of research rated world‑leading or internationally excellent (REF 2021).

Leicester ranks 25th in the UK in the 2026 Times Higher Education World University Rankings and 33rd in the Complete University Guide 2027, and is top 10 in the UK for student experience and top 15 for student satisfaction in the 2025 National Student Survey.

Named the Daily Mail University of the Year 2025 and shortlisted for the Times Higher Education University of the Year 2024 and The Times and The Sunday Times University of the Year 2025, Leicester is driven by a commitment to excellence, inclusion and meaningful global impact.

 

If you would rather not receive future communications from University of Leicester, let us know by clicking here.
University of Leicester, University Road ., Leicester, . LE1 7RH United Kingdom

 

 

 

For further information please contact the University of Leicester press office on 0116 252 2160 or press@le.ac.uk       

 

 

The Southampton Clinical Trials Unit (SCTU) is a Cancer Research UK (CRUK) core-funded CTU with expertise in the design, conduct and analysis of interventional, multi-centre clinical trials. The CTU is based within the University of Southampton with offices at the University Hospital Southampton NHS Foundation Trust Southampton General Hospital site. The unit is part of the NIHR Research Support Service University of Southampton Hub and partners in the NIHR Southampton Biomedical Research Centre. For more information, visit the SCTU website or follow us on social media: LinkedIn, Bluesky, Facebook, X, and Instagram.

 

Asthma + Lung UK is the only charity in the UK fighting for everyone with a lung condition, aiming for a world where everyone can breathe with healthy lungs. We fund cutting-edge research and provide advice and support for the 12 million people who will get a lung condition during their lifetime. We also campaign for clean air and for better NHS diagnosis and treatment. For further information visit asthmaandlung.org.uk.     

 

The NIHR Biomedical Research Centre Leicester

 

The National Institute for Health and Care Research (NIHR) Biomedical Research Centre (BRC) Leicester is part of the NIHR and hosted by the University Hospitals of Leicester NHS Trust in partnership with the University of Leicester, Loughborough University and the University Hospitals of Northamptonshire NHS Group. 

 

The NIHR BRC Leicester undertakes translational clinical research in priority areas of high disease burden and clinical need. These are: 

• Respiratory and infectious diseases 
• Personalised cancer prevention and treatment 
• Lifestyle (including diabetes) 
• Environment and health 
• Data innovation for multiple long term health conditions and ethnic health 
• Cardiovascular disease 

 

The BRC harnesses the power of experimental science to explore and develop ways to help prevent and treat chronic disease. It brings together 120 highly skilled researchers, 45 academic ‘rising stars’, more than 90 support staff and students and over 450 public contributors. By having scientists working closely with clinicians and the public, the BRC can deliver research that is relevant to both patients and the professionals who treat them. www.leicesterbrc.nihr.ac.uk  

 

The mission of the National Institute for Health and Care Research (NIHR) is to improve the health and wealth of the nation through research. We do this by:
 

• Funding high quality, timely research that benefits the NHS, public health and social care;
• Investing in world-class expertise, facilities and a skilled delivery workforce to translate discoveries into improved treatments and services;
• Partnering with patients, service users, carers and communities, improving the relevance, quality and impact of our research;
• Attracting, training and supporting the best researchers to tackle complex health and social care challenges;
• Collaborating with other public funders, charities and industry to help shape a cohesive and globally competitive research system;
• Funding applied global health research and training to meet the needs of the poorest people in low and middle income countries.

NIHR is funded by the Department of Health and Social Care. Its work in low and middle income countries is principally funded through UK international development funding from the UK government.

 

Leicester’s Research Registry was launch in May 2021 and will share opportunities to get involved in health research taking place in Leicester’s Hospitals, or being run with their research partners, such as the University of Leicester and Loughborough University, in their National Institute for Health and Care Research (NIHR) Biomedical Research Centre, Clinical Research Facility and Patient Recruitment Centre: Leicester.

 

To sign up to the registry, potential volunteers need to be over 18 years of age, live in the UK, and have a valid email address. You also have the option to select if there are particular areas of health research you are interested in. You will then receive regular updates on all the exciting opportunities to participate in the hospitals’ research.

To sign up, visit www.leicestershospitals.nhs.uk/researchregistry. You can also visit the dedicated Facebook page.

 

---

Method of Research

Randomized controlled/clinical trial

Subject of Research

People

‘Cooling Poverty’ Affects 2Bln As Heat Risks Swell



Children cooling off with piped water in Khan Village, Lao PDR in 2015. The World Meteorological Organization has warned of hotter than normal temperatures across the globe in the coming months due to the El Niño effect. Copyright: Asian Development Bank (CC BY-NC-ND 2.0)

June 8, 2026 
By Mohammed El-Said


More than 2 billion people in some of the poorest communities face significant levels of “cooling poverty”, where they are exposed to life-threatening heat without safe or affordable ways to cool themselves, according to new analysis.

Increasingly frequent and intense hot spells are causing spikes in health risks and deaths globally and those most at risk are those with the least resources to adapt, a study published in Nature Sustainability warns.

It comes as parts of India and Pakistan are grappling with temperatures topping 45 degrees Celsius.

The World Meteorological Organization has also warned of hotter than normal temperatures across the globe in the coming months due to the El Niño effect.

“Cooling poverty and what we call systemic cooling poverty refers to conditions in which individuals are prevented from attaining thermal safety, not simply because they lack an air conditioner,” Giacomo Falchetta, a scientist at the Euro-Mediterranean Center on Climate Change and the study’s lead author told SciDev.Net.

Heat risk is compounded when people lack not only cooling devices, but also adequate housing, healthcare and information about heat risks, he explained.

The study analysed data from more than a million households in 28 countries, most of them in low- and middle-income countries. Of nearly three billion people covered, about 1.2 billion live in areas with moderate cooling poverty, around 550 million face severe cooling deprivation, and about 600 million experience high deprivation across multiple dimensions, the study calculated.

Aziza Mohamed, professor of human geography and urban studies at Cairo University in Egypt, says the study shifts the debate on heat from a purely climatic issue to a developmental, social and spatial one.

“The real danger does not come from climate alone,” she told SciDev.Net. “It comes from the interaction between heat, poverty, housing quality, weak health services and the absence of suitable infrastructure.”

South Asia and Sub-Saharan Africa are the two regions most affected, for different reasons. In South Asia, almost 80 per cent of the population in the sample live in regions where the systemic cooling poverty index exceeds 55 out of 100.

In countries such as India, Nepal and Bangladesh widespread heat and humidity exposure combines with large outdoor labour forces and gaps in education, information access and cooling policy, says Falchetta.

Harjeet Singh, climate activist and founding director of the Satat Sampada Climate Foundation, says South Asia is “at the absolute frontlines of the climate crisis”, facing “a lethal combination of geographic vulnerability and systemic economic inequality”.

The danger is not heat alone, but humid heat, which makes the body less able to cool itself through sweating, explains Singh. In a region of high population density and informal labour, retreating into an air-conditioned room is not an option for most.

In Sub-Saharan Africa, the study finds that extreme heat risks are driven by weak protective infrastructure. Falchetta named Ethiopia, the Democratic Republic of Congo (DRC), Rwanda and Malawi as countries with extremely high deprivation in housing quality, water and sanitation, energyaccess, and cooling green and blue spaces.

Even where heat and humidity is less extreme, he warned, “the near-total absence of protective infrastructure means any intensification of heat would be catastrophic”.

The study estimates that about 1.5 billion people live in areas with inadequate infrastructure, and health conditions to deal with heat. More than 90 per cent of people living in Ethiopia, DRC, Rwanda, Malawi and Zambia fit this category.

In contrast, Egypt had relatively low levels of “cooling poverty” (40 out of 100), despite 82 per cent of its population being exposed to hazardous heat and humidity. It performed well across infrastructure, social and policy dimensions.

Risk factors

Poor housing multiplies heat risk, as homes built from rudimentary roof, floor and wall materials can become heat traps rather than refuges, the research highlights.

Singh points out that millions of urban poor people live in settlements with tin or asbestos roofs, which can make indoor temperatures up to five degrees Celsius hotter than outside. Unreliable electricity, unsafe water and poor sanitation also limit cooling, hydration and protection.

Weak healthcare further increases the danger, according to the study. It identified Nepal, Yemen, Pakistan, Bangladesh and Guatemala among the most deprived countries in this regard. Limited healthcare access, explains Falchetta, means treatable heat-related illness can be fatal.

Outdoor workers in agriculture, construction, transport and informal trade are particularly at risk, spending long hours under direct sunlight.

Women, ethnic and religious minorities, elderly people, poorer households and children are disadvantaged because they are more likely to live in poor housing, lack information and healthcare, and have fewer resources to adapt, Falchetta notes.

Education and working standards were the most widespread form of cooling poverty identified in the study. Around 2.2 billion people, about 75 per cent of those studied, live in deprived areas under this lens. India ranks highest, with 95 per cent of its population facing deprivation, followed by the DRC, Nepal, Rwanda and Malawi.

The study and experts agree that air conditioning, which consumes large amounts of energy and strains fragile grids, cannot solve the problem.

“Addressing cooling poverty by distributing air conditioners alone would be neither sufficient nor sustainable,” Falchetta said.

Singh is in no doubt: “We absolutely cannot air-condition our way out of this crisis.”
Cooling strategies

Instead, the study calls for coordinated, low-cost policies across housing, water, health, labour and urban planning.

Falchetta says better housing design can reduce indoor temperatures without energy inputs. Expanding trees, parks and water bodies can provide community-level cooling, while improving water and sanitation works as both a cooling and health intervention.

Coating tin or concrete roofs with solar-reflective white paint can reduce indoor temperatures by two to five degrees Celsius, says Singh, while straw and clay offer affordable insulation. He calls for public cooling shelters with free drinking water for outdoor workers, restoring urban green spaces and water bodies, and expanding efficient BLDC (brushless direct current) fans.


Chandni Singh, associate professor at the Indian Institute for Human Settlements, says policy is crucial. Protection of blue and green infrastructure and climate-sensitive building codes, such as India’s Cool Roofs Policy, can help, she says.

Falchetta believes heat-health action plans could reduce cooling poverty, especially in Sub-Saharan Africa, where they are largely absent.

Cities in India, Pakistan and Bangladesh have introduced heat action plans, but many lack legal force and budgets, says Harjeet Singh. Governments, he argues, should adopt mandatory rest breaks for outdoor workers, climate-resilient building codes for affordable housing, and financial compensation for daily-wage workers when heat advisories force them indoors.

But Chandni Singh warned: “You cannot adapt your way out of extreme heat endlessly. There are limits to extreme heat adaptation.”

This piece was produced by SciDev.Net’s Global desk.
Mohammed El-Said writes for SciDev.Net.
View all posts by Mohammed El-Said →

Heat, Inequality, And The ‘Right To Cool’ – Analysis

May 28, 2026 
Observer Research Foundation
By Soma Sarkar

Urban heat has emerged as one of the most unequal climate risks in cities. India is currently experiencing a severe heatwave, with temperatures routinely crossing 44°C in multiple cities. During the unprecedented heatwave in late April 2026, India accounted for 95 of the world’s 100 hottest cities.

Although rising temperatures affect an entire city, spatial inequalities and diverse socioeconomic conditions stratify levels of exposure and vulnerability within the population. Informal settlements, areas with limited tree cover, and neighbourhoods characterised by poorly ventilated housing tend to experience more intense thermal stress. At the same time, the ability to seek refuge from heat is unequally distributed between those who can rely on private cooling infrastructure, such as air conditioning, and those who cannot. For the underprivileged, shared urban commons, such as parks, lakes, shaded areas, and community lands, have traditionally served as places of respite that provided informal cooling refuges. However, rapid urbanisation and urban densification have engulfed even these shared spaces, concretising land into built areas and intensifying urban heat island effects.

These inequalities become more apparent when viewed through the lens of labour. Low-income populations, particularly informal workers, such as street vendors, delivery workers, sanitation workers, and construction labourers, experience higher and more intense heat exposure because their livelihoods require prolonged outdoor presence. Though they sustain the everyday functioning of urban economies, urban planning often overlooks where they can find refuge. For many, avoiding outdoor work during peak heat hours can threaten their earnings and job security. Consequently, while heat advisories may encourage residents to stay indoors, large segments of the urban workforce have little choice but to continue toiling in hazardous conditions.

This scenario raises critical questions about urban justice: If access to cooling and climate protection is mediated by income and property ownership, what does that mean for the promise of an inclusive city? Do the people whose labour sustains urban economies have a right to shade, rest, and thermal refuge?

Spatial Inequalities in Heat Exposure and Refuge

The weakening of monsoonal cooling and extension of the high-heat period across South Asia by 2026 El Niño pose a greater risk to India. Indian cities have warmed at roughly 0.53°C per decade in night-time land surface temperature. Approximately 60 percent of the increased heating in Indian cities can be attributed to urbanisation and the increase in concrete surfaces, asphalt, metal roofs, and glass curtain walls. The indicators of ward-level heat exposure are informal settlement density, low green cover, minimal tree canopy, proximity to industrial land uses, and the predominance of thin metal or asbestos roofing, all of which correlate with income conditions. For example, Mumbai has a differential of 5.6°C between settlements separated by approximately 2 kilometres, with Dharavi having a mean land surface temperature of 35.9°C, compared with 30.3°C in Matunga. Approximately 37 percent of Mumbai’s households have tin roofs that trap radiant heat, with indoor temperatures exceeding 40°C during peaks. In Mumbai’s M/East Ward, heat worsens for the marginalised population exposed to the mountains of waste at the Deonar landfill. Similarly, slum surveys in Ahmedabad revealed that 85.5 percent of the sampled households experienced significantly higher heat than households in non-slum areas.

Beyond exposure, the capacity to seek refuge from heat is itself unequally distributed. Cooling technologies impose a dual inequality: their capital and operating costs exclude the urban poor on the one hand, and their condensers raise outdoor temperatures on the other. This scenario creates segregated atmospheres and externalises the thermal cost to vulnerable groups. This dual inequality is most evident in informal settlements in cities like Delhi, which co-exist alongside affluent neighbourhoods. Low-income households may spend up to 8 percent of their budget on cooling, which can lead to energy poverty.

This dual inequality is not confined to Indian cities. In Phoenix, Arizona, for example, Hispanic majority neighbourhoods are found to be 5°C hotter than the suburbs, with tree equity gaps persisting despite heat plans. Santiago, Chile, mirrors this in its peripheries, where migrant workers inhabit heat-vulnerable hillsides.

Heat and Informal Labour

In India, the informal sector employs more than 200 million workers, many of whom work in outdoor or semi-outdoor environments with no institutional protection against extreme heat. In 2024, India lost about 247 billion labour hours due to heat, resulting in economic losses worth US$194 billion. For daily wage workers, heat-related work stoppages mean immediate income loss, with no paid leave or social protection, forcing many to continue working under dangerous conditions. Women in high-heat-vulnerability areasexperience fatigue, dizziness, dehydration, and gastrointestinal illnesses, leading to income losses during the summer months of April to June.

Street vendors, construction labourers, sanitation workers, delivery riders, waste pickers, domestic workers, and agricultural labourers in peri-urban settings are among those most exposed. Their occupational heat exposure is not simply a function of outdoor temperature, but it is intensified by the thermal properties of the surfaces they work on or under (asphalt, concrete, metal), the absence of shade, limited access to drinking water and rest facilities, and the economic perils of voluntarily withdrawing from heat-exposed work. In this context, standard heat advisories such as “Avoid getting out in the sun, especially between 12:00 noon and 03:00 pm” and “Avoid strenuous activities when outside in the afternoon” are often impractical for informal and low-income workers, for whom compliance may directly translate into wage and livelihood losses.

This shows that the urban heat crisis is a structural emergency exposing deep faultlines in how Indian cities are planned, governed, and for whom. The policy response has remained largely technocratic, fragmented, and insufficiently attentive to the dimensions of labour justice and spatial equity. Cool roof programmes, heat action plans, and early warning systems are welcome and necessary, but they are insufficient so long as they do not address the underlying conditions that make large sections of the population chronically exposed to thermal heat.

From Fragmentation to Integration: A Just Urban Climate Agenda

The heat crisis reveals an urgent need to revisit urban governance through the twin lenses of the urban commons and climate justice. Parks, lakes, tree canopies, and shaded public squares are critical life-support infrastructures. Urban heat is deeply intertwined with the water crisis as green cover vanishes, impervious surfaces expand, groundwater tables decline, and urban flooding intensifies. It is also linked to air quality, as heat inversions trap pollutants and increase respiratory risks. Moreover, heat vulnerability increases with housing precarity, as those in informal settlements lack insulated walls, cross-ventilation, or access to reliable electricity for cooling. These are not disparate crises requiring targeted solutions but interlocking symptoms of a single, deeper failure of urban planning philosophy.

Indian cities must adopt an Integrated Urban Climate Resilience Framework that would treat heat mitigation, stormwater management, urban greening, air quality improvement, and housing resilience as interdependent goals. Cities like Medellín and Singapore have demonstrated that urban ecological infrastructure, when planned holistically, can simultaneously cool cities, manage floods, enhance biodiversity, and improve liveability for all residents. Parks, lakes, urban forests, and shaded public spaces must be formally recognised in urban master plans and municipal budgets as critical climate infrastructure, ring-fenced from encroachment and commercial development.

The city-level Heat Action Plans must be expanded and reoriented to centre the rights of outdoor workers, providing statutory protection, including mandatory rest breaks, access to shade and potable water at worksites, flexible timing provisions during peak heat hours, and health insurance coverage for heat-related illnesses. Governments must also provide income security against the time lost due to heat advisories that urge people to remain indoors at certain times of the day. The lives of those who build and sustain the city must have the ‘right to cool’ and not be treated as acceptable casualties of the heat.

About the author: Soma Sarkar is an Associate Fellow with the Urban Studies Programme at the Observer Research Foundation.

Source: This article was published by the Observer Research Foundation.

 

India’s Urban Heat Crisis is Also a Housing Crisis

Anusreeta Dutta | 11 May 2026

• 
  
• 
  

Housing quality and inequity in cities has turned into a public health problem in the era of climate change.

Image Courtesy: Wikimedia Commons

The heat is rising in India’s cities. But the crisis isn’t hitting everyone equally. Every summer we have worrying reports of rising temperatures, collapsing infrastructure, water shortages, and heat-related deaths. Cities, such as Delhi, Kolkata, Ahmedabad, Hyderabad, and Mumbai are seeing increasing intensity and duration of heatwaves, with the India Meteorological Department issuing several warnings of high heat conditions. But the mainstream discourse on heat in Indian cities is often constrained to heat as a climatic or environmental phenomenon. Indeed, India’s urban heat crisis is intrinsically tied to the country’s growing housing inequity.

Now, heat is not felt only outside. The most damaging temperatures are increasingly trapped inside poorly ventilated homes, or those without cooling systems, green cover, or thermal protection. Heatwaves are no longer just environmental disasters for millions of urban poor living in informal settlements, congested rented dwellings, and low-income neighborhoods.

That is why India’s urban heat problem is fundamentally inequitable. “Where you live, what your home is made of, whether you have energy, and the cost of cooling are all increasingly important factors in your ability to cope with extreme heat.” 

The situation was worsened by the urban heat island effect. Concrete structures in tight clusters, asphalt roads, glass infrastructure, shrinking bodies of water, and disappearing green spaces absorb and trap heat all day long. Instead of cooling, cities continue to radiate stored heat back into the environment during the night.

Poorer populations are very vulnerable, whereas wealthier areas often mitigate this with air-conditioning, insulated homes, and green infrastructure. Informal settlements with tin roofs, plastic sheets, asbestos constructions, and poorly ventilated apartments intensify summer heat. In these communities, indoor temperatures can far exceed ambient temperatures, especially in dense urban areas with little air flow.

This exposes a truth that is often overlooked in climate policy conversations: housing quality has turned into a public health problem in the era of climate change.

India has seen rapid urbanisation but not much investment in affordable and climate-resilient housing. Millions of migratory workers and low-income families still live in settlements without basic infrastructure, such as water, sewage, power, and cooling systems. These vulnerabilities are particularly dangerous in heatwaves. Sometimes families have to make hard decisions between paying for their electricity bills for cooling systems and coping with rising food and living costs.

Many households see little relief even from fans as indoor temperatures remain dangerously high throughout the night. Air-conditioning still remains out of the reach of a large section of India’s urban population, both in terms of cost and irregular electrical supply. And if the temperature goes up even more, cooling risks becoming another form of inequity.

Women, children, the elderly, and informal labourers are among the most intensely pressured groups in these living conditions. Women who have longer working hours in the home as caregivers or housekeepers are often exposed to persistent heat. The elderly and people with pre-existing illnesses are particularly vulnerable to dehydration, cardiovascular stress, and respiratory difficulties during prolonged heatwaves. Children growing up in overheated communities face higher health risks, including sleep disruption, hunger, and cognitive stress from exposure to high heat.

Urban housing and public health planning are thus no longer separate.

Housing and heat are also tightly linked to labour inequality. Many informal workers, such as construction labourers, street sellers, sanitation workers, delivery workers, domestic workers, and manufacturing workers form the backbone of the economy in India’s cities. After long hours of outdoor exposure to heat, they go home to homes that have little physical recovery from high temperatures. During heatwaves, occupational and residential exposures become mixed.

This results in what could be termed a heat vulnerability cycle. Workers are subjected to extreme heat, outdoors during the day and indoors at night. Without adequate recovery, heat stress builds up over time, which increases longer term health risks and decreases work productivity. Thus, climate change begins to affect not only health outcomes but also economic systems and labour sustainability in metropolitan areas.

India’s existing urban planning frameworks are still not prepared to deal with this reality. Cities such as Ahmedabad and Delhi have adopted Heat Action Plans that have improved emergency response, awareness campaigns, and early warning systems. However, most of these strategies are still applied with an emphasis on outdoor heat control rather than indoor thermal sensitivity. There are conversations in the public square about rationing water, issuing heat advisories, and setting up temporary cooling shelters, but the structural housing piece is often absent.

India’s affordable housing programmes have focused on quantity over climate resilience in the past. Government housing programmes have increased access to housing for many families, but thermal comfort, ventilation, reflecting materials, green design, and heat-resistant construction are often ignored. As climate conditions worsen, this strategy may be less viable.

The problem isn’t just building more houses. It’s about building homes that can withstand future climate changes. Urban planning experts increasingly argue that climate adaptation should be embedded directly in housing policy. These include cool roofs, reflective building materials, shaded public spaces, improved ventilation systems, passive cooling design, rooftop gardens, urban tree cover, and smarter settlement planning.

Several Indian towns have tried out cool-roof projects, painting rooftops in vulnerable communities with reflective white coatings, and have found promising results in lowering inside temperatures. But such measures are limited in the face of the scale of India’s urban housing need. 

This is a political question too. In India, real estate-led urbanisation has often been marked by a focus on commercial growth, gated infrastructure, and speculative building, rather than equitable and climate sensitive planning. Wetlands, urban woods, lakes, and open spaces that once cooled our cities have been lost to rapid development. Environmental damage and housing inequality increasingly reinforce each other in many places, intensifying heat vulnerability for low-income populations.

Delhi is a no-brainer. Much of the city suffers from substantial urban heat island effects because of the vast construction and reduction of green cover. Informal colonies and resettlement zones can have much higher exposure to heat than affluent neighborhoods with better infrastructure and tree density. Similar patterns can be observed in Kolkata, Chennai, Hyderabad, and Mumbai where informal housing clusters are disproportionately affected by intense heat conditions.

The future of India’s cities will, therefore, hinge on whether they can forge sustainable and equitable forms of climate adaption. If housing is not included in climate policy, heatwaves could become one of the most serious urban inequality issues in the coming few decades.

The heat crisis is not a seasonal inconvenience any longer. It is reshaping urban vulnerability. Each temperature rise is a sign of a larger structural problem of housing injustice, infrastructural disparity, labour precarity, and unequal access to climate protection.

Weather warnings can’t solve India’s urban heat emergency. It calls for rethinking how cities are built, who they’re built for, and why climate resilience begins at home.

The writer is a columnist and climate researcher with experience in political analysis, ESG research, and energy policy. The views are personal.