More than 20 cities across India surpassed temperatures of 42°C as of early April this year, with several large cities including Delhi and Mumbai under yellow alert for extreme heat.

This unusually intense heat continues as the Indian Meteorological Department (IMD) predicts above-normal number of heatwave days, maximum as well as night temperatures in its outlook for April-June 2025.

As most parts of the country continue to face scorching heat for the third year in a row, there is a need for accelerated and systemic action towards building robust healthcare systems, heat resilient urban planning and nature-based solutions for mitigating the impacts. 

Recent studies indicate that heat kills more people than any other climate related extreme events each year and negatively affects nearly every human activity and society worldwide. During 2000-2019, on average there were 489,000 deaths per year from extreme heat globally. In India, heat waves in just the March-June period of 2024 caused over 100 deaths and 40,000 recorded cases of heat strokes as per Government estimates, not counting the concomitant impact on existing conditions like heart or kidney diseases.

Unless carbon emissions substantially decrease, up to 75% of the global population could face deadly heatwaves by 2100, substantially increasing the direct impacts on human health and mortality, especially in the most vulnerable groups including expectant or breastfeeding mothers, children and the elderly.

For context, each 1°C rise in temperature is linked to a 6% increase in preterm births and a 16% rise in stillbirths during heatwaves. Besides, heat stress has also been known to exacerbate mental health and social issues such as gender-based violence. 

Safeguarding lives and livelihoods

While the readiness of the healthcare system to respond to heat-related emergencies is critical for immediate care under surge conditions, building resilient health infrastructure assets and facilities is equally important.

Solutions to respond to this issue will need to be multi-dimensional, multi-fold and multi-level. From designing heat resilient health infrastructure that embraces both efficient design and passive and nature-based techniques, to tailor-making clinical pathways, including ICD classifications for heat related impacts on populations – all will need to be focused upon.

Similarly, our current response to heat related morbidity is severely challenged by a lack of trained health workforce that does not have heat or extreme climate event related impacts in their curricula. As we plan these, policy makers will need to appreciate some of the trade-offs that our response would require. For instance, expansion of HVAC in health facilities is known to improve patient outcomes, both during or without a heat wave.  

A Japanese study indicates that about 36–47 % of heat-related deaths could be averted by air conditioning use under various urban warming scenarios. This benefit would however come at the cost of increased emissions from health facilities. Hence, the need to adapt, mitigate and build resilience needs to be equally addressed for a holistic response. 

Heat-related impacts on work productivity and livelihoods are also cause for socio-economic and equity concerns. More than 70 per cent of the global workforce – 2.4 billion people – are now at high risk of extreme heat as per International Labor Organization. South Asia alone is projected to lose 5.3% of its working hours, equivalent to 43 million jobs, to heat stress by 2030.

Effective coping strategies for mitigating livelihood impacts of the most vulnerable groups, including informal and construction workers, street vendors and frontline workers are especially important. Many of these disproportionately affected populations are already adapting informally.

However, there is a need for legal recognition and structured measures through worker protection guidelines and workplace interventions, such as scheduled rest breaks, adapted work hours, and rest-shade-rehydrate (RSH) programs. At the same time, community led interventions such as designated active or passive cooling shelters run in collaboration with local governments and other stakeholders may provide significant positive impacts where formal workplace interventions may not be possible. Though this would require clear Standard Operating Procedures (SOPs) for effective operations and management of cooling shelters. 

Addressing urban heat islands

At a systemic level, cities, as hubs of population and infrastructure, are more prone to heat stress than rural areas due to a combined result of increasing frequency and intensity of heat waves along with the urban heat island (UHI) effect. UHI makes cities 4-6 degrees hotter than adjoining rural areas; it is also a key factor for warmer night-time temperatures as concrete buildings, hard surfaces and pavements, trapping heat in the day are unable to dissipate it efficiently at night. These above-normal night temperatures do not allow the human body to cool down, leading to sustained heat stress and heat stroke situations. 

Several cities in India and beyond are already taking steps to address UHI and indoor ambient heat through cooling measures such as cool roofs and cool pavements. Informal settlements in Delhi and Ahmedabad have been using heat-reflective paint on roofs, which is both a cost-effective and energy-saving measure, for lowering indoor temperatures. On the other hand, cities including Tokyo and Los Angeles are providing incentives to local infrastructure development agencies for promoting cool pavements. While these pilot initiatives provide direct benefits to the local communities, studies in the UK have shown that cool roofs, when implemented across a city, could offset 18% of heat-related mortality associated with the heat island effect. There is, therefore, a need to explore ways and means for scaling and replicating these interventions at the city level.  

Another ongoing discourse in the context of extreme heat is that of nature-based solutions, also known as blue-green infrastructure. Nature-based solutions such as wetlands, green roofs, vertical gardens and permeable surfaces address urban heat and flooding while at the same time reducing energy consumption. Paris and Milan have transformed public spaces such as schoolyards and plazas into urban ‘oases’ that are cool community spaces to beat the heat. Several Dutch cities are going a step beyond, implementing city-scale community led initiatives to convert paved surfaces to green areas. In India, Chennai is actively restoring its wetlands that will not only act as sponges to address the city’s recurrent flooding woes but also help bring down the ambient temperatures and improve air quality. However, the application of nature-based solutions at scale requires structuring financial mechanisms and instruments to support large-scale implementation, maintenance and upkeep besides policies, norms and standards for project designers and investors to gain confidence. 

Coordinated heat action planning and governance 

Finally, effective heat stress management in cities requires coordinated and collaborative action across urban planning, energy, health, and related sectors at three levels: 

One, setting up improved early warning systems and access to risk information for tailored action and policy making, as well as real-time tracking and data on heat-related health risks. For instance, the Ministry of Health guideline on state heat health action plans prescribes reporting of Heat-Related Illness and Death Surveillance in the form of daily submission of data on heatstroke cases and deaths, emergency attendance and total deaths.

Two, formulation of local Heat Action Plans (HAP) with horizontal integration for multi-stakeholder action, and vertical integration with national level plans and policy frameworks. Ahmedabad Heat Action Plan is a much-cited example in the Indian context. The success of Ahmedabad HAP lies in its cohesive heat response with community resilience-building and implementation of active adaptation measures such as cool roofs, coupled with annual evaluation and review process to bring down heat related illnesses and deaths.  It is equally important to pivot towards long-term adaptation action. 

Several India cities including Mumbai, Bengaluru, Chennai have outlined resilience building measures for climate related extreme events including heat and urban flooding as part of their city climate action plans. Most recently, BBMP (Bruhath Bengaluru Mahanagara Palike) budget for 2025-26 has earmarked a dedicated climate action plan implementation budget. Convergence of HAPs with local city climate action plans and budgets can help amplify action. Besides, vertical integration under national policies, plans and codes can be a game changer. India’s existing National Mission on Sustainable Habitat 2021-2030 recommends preparation of local heat island maps to inform mitigation strategies and integrating norms and standards to address climate risks in the Model Building Bye- laws and National Building Code, 2016 for adoption by cities. Moreover, integrating heat resilience in the ongoing National Adaptation Plan formulation exercise can go a long way in enabling local action and budget allocation. 

The third, and perhaps the most critical, is setting up dedicated institutional structures and strengthening capacities to coordinate, formulate and implement heat action in cities. Globally, we have seen cities including Athens, Melbourne, Freetown and Dhaka North among others appointing Chief Heat Officers while others such as Boston developing local heat guidance documents and tools. As extreme heat events increase in frequency and intensity with a changing climate, with communities and cities facing the brunt of the impact, systemic readiness of infrastructure and governance structures will go a long way in enabling cohesive and accelerated action!

By: Ms Raina Singh, Lead - Global Infrastructure Resilience Report at CDRI, and Dr Karan Thakur, Healthcare administrator at Apollo Hospitals.

The views and opinions expressed in this blog are those of the authors and do not necessarily reflect those of the Coalition for Disaster Resilient Infrastructure (CDRI).