Inside cooling shelters with IIHS

In this short interview, the Indian Institute for Human Settlements (IIHS) takes us through a crucial solution to heat stress – cooling shelters; the need for these shelters, key features, passive design techniques, projected benefits, and the phased implementation. 

How did IIHS identify the need for cooling shelters, and what factors influenced this decision?

IIHS is committed to working on the equitable and sustainable transformation of India. Summer temperatures in India have been consistently rising over time, with projections indicating a further rise of up to 4°C by 2100, and reports from the Centre for Science and Environment highlighting the increase in extreme weather events, including heatwaves, over the past few decades. The country experienced record-breaking heatwaves in 2024, with temperatures exceeding 500C in multiple regions. Projections suggest that temperatures in many parts of India could exceed survivability thresholds for even healthy individuals by 2050.  

There’s already evidence of high temperatures taking their toll on the productivity, health, and economic well-being of Indians, with the country’s informal workforce of 38 crore - most of whom work outdoors in farms, streets, construction sites, and other workplaces lacking protection from heat exposure - being the most vulnerable. In recent years, heat has led to estimated annual economic losses of Rs 11.6 lakh crore, 40,000 cases of stroke. 

IIHS has developed a proposition to address the high priority policy issue of climate change and is targeting a cooling shelter solution that will be deployable across the country and render economic and health benefits to the poorest and most vulnerable groups in the country. Planned locations for these installations include Punjab, Haryana, Tamil Nadu, Karnataka, Kerala, Madhya Pradesh, Rajasthan, NCR, Uttar Pradesh, and Maharashtra.

What are the key features of these shelters, and how do they ensure comfort for workers during extreme heat conditions?

The proposed cooling shelter will provide relief to outdoor workers during the hottest parts of the day. Each cooling shelter will be about 1,000 sq ft in area including a main covered space of about 250 sq ft and a shaded verandah (providing a transition space that will help individuals adapt and acclimatise before entering the cooler interior). The shelter will be equipped with a rest area for heat affected individuals, ceiling fans, toilets, charging points, and first aid kits.  

Importantly, the shelter will be modular, easy to assemble, and built with sturdy yet lightweight material, such that there’s flexibility in its deployment in locations of most need, scarce land is not permanently occupied, transaction costs for building permissions are saved, and the structure itself is able to resistant to wind and extreme weather.  

Also, the shelter will be designed to ensure functionality even during grid outages and will use shading, cool roof, insulation, thermal mass, cross-ventilation, and low-energy cooling technologies to minimise energy use.  

Can you elaborate on the passive design techniques used in the shelters, and how do they contribute to energy efficiency and sustainability?

A thermal simulation for the 2015 heatwave period in Jodhpur showed that the proposed shelters will maintain wet-bulb globe temperatures up to 8°C cooler inside, significantly reducing heat stress. Strategies such as enhanced cool roofs with high solar reflectance, increased thermal mass using stacked water bottles, and improved ventilation through natural airflow can significantly reduce indoor heat stress. Additionally, a combination of night ventilation and thermal storage can retain cooler temperatures for extended periods. 

What are the projected benefits of deploying these shelters across cities, and how do you measure their impact on reducing heat stress and saving lives?

Such cooling, in turn, will protect the shelter’s users from exposure to peak heat and help them avoid sickness and consequent losses in earnings and costs of healthcare. Estimates suggest that these losses and costs could be as high as Rs 27,000 per individual per instance of heat-induced sickness. The 20 shelters envisaged will together benefit 8,000 outdoor workers annually in terms of reduced economic losses and healthcare costs to the tune of Rs 36 crores over a 10-year life of a shelter.  The solution, when scaled appropriately at the national level, has the potential to save 7000 lives annually and reduce India’s healthcare burden by Rs 10,800 crore per annum. 

Could you walk us through the two-phase implementation plan, and how community engagement and stakeholder input are integrated into the design of the shelters?

Phase 1: Design development and prototyping

This set of activities, proposed to be undertaken over the first year, is intended to ensure that shelter design and future arrangements for its operations are aligned with community needs and views and achieve a cost-efficient, easy-to-construct, heat-resilient, and user-friendly shelter ready for wider deployment. This is expected to involve close engagement with communities and building, stress-testing, and iterating the shelter such that the final design is robust and user-friendly. The design, at each stage, will be refined based on technical evaluation and user feedback and will involve testing of technologies.   

Phase 2: Deployment

The deployment will be aimed at demonstrating the effectiveness of the shelters in 20 cities spanning diverse heat-prone environments and influence long-term demand and scale-up beyond the initial deployment, over a two-year period. This will involve installation of 20 shelters in different cities, each with a designated operating partner and a model for sustainably meeting operating costs, and amplifying the experience with the shelters to influence a wider set of actors to support the scale-up of the solution, including through instruments such as city, state, and national heat action plans. 

About IIHS 

The Indian Institute for Human Settlements (IIHS) is a national education institution committed to the equitable, sustainable, and efficient transformation of Indian settlements. IIHS conducts research, practice, academics, and capacity building work with a particular focus on the challenges and opportunities of India's urban transition. The IIHS University hosts integrated programmes of quality campus-based education and research, training and lifelong learning for working professionals, distance and blended learning, and an array of practice and advisory services.