What Bangladesh can learn from the Ahmedabad Heat Action Plan

This year in April, Bangladesh recorded the longest heatwave in 76 years. According to meteorologists, sporadic rain might lower the temperature in the next few days but another heatwave will soon follow. 

At least 10 people have died from heat strokes in Bangladesh in the last week of April. Unofficially, the number of heatwave deaths was around 35 as of April 28. The season's highest temperature, 43.8°C, was recorded in Jashore on April 30.

For the last decade or more, Bangladesh and the neighbouring countries have been facing severe consequences of climate change such as unprecedented heat waves, frequent cyclones, flash floods etc. Even if the world immediately stops emitting carbon – the key instigator for climate change – altogether, the temperature will still keep rising for the next couple of decades. 

So the only option in hand for a country like Bangladesh is to adapt to the situation and work with a damage control strategy. In fact, it can learn a few lessons from the Ahmedabad Heat Action Plan (HAP) in India which was implemented after the 2010 tragedy. 

On 21 May, the temperature reached 47°C in Ahmedabad, a city of 5.5 million people. As a result, on that single day, the daily mortality number increased from 100 to 310. 

Between 20 May and 27 May, there were 800 additional deaths. In May, the hot spell killed over 1,300 people in Ahmedabad. 

After this tragedy, the Ahmedabad city government, Indian Institute of Public Health Gandhinagar and Natural Resources Defense Council (NRDC) – an international NGO, formed a three-way partnership to develop the HAP, which was first implemented in 2013. 

According to a research titled 'A Successful Heat Wave Prevention in Ahmedabad Calls for Segregated Health Record: Highlights from Existing Heat Action Plan' published on the Aerosol and Air Quality journal, the implementation of Ahmedabad HAP has led to avoiding 1,190 deaths per year. 

Professor Dileep Mavalankar, a Former Director and Honorary Professor at the Indian Institute of Public Health, Gandhinagar, was an instrumental figure in developing the HAP. 

The Business Standard recently spoke to him in detail about how the HAP is saving lives in Ahmedabad through simple measures such as issuing heat alerts, planting more trees, and promoting cool roofs in slums.   

Professor Dileep Mavalankar, a Former Director and Honorary Professor at the Indian Institute of Public Health, Gandhinagar. Sketch: TBS

Look at the overall deaths

Last month, Professor Mavalankar delivered a presentation on the HAP at a media training on 'Understanding & Reporting Climate, Air Pollution & Health' in Kuala Lumpur, which was a side project of the 2024 Planetary Health Summit held in the Malaysian city. 

"Whatever number of deaths per day we see – one person or 10 or 20 people per day – is actually just a tip of the iceberg," Mavalankar told us. "You should ask the Dhaka city government to declare how many people are overall dead – all causes included – on a daily basis." 

"Like I said in my presentation (during the Kuala Lumpur event), that although 800 additional deaths occurred in one week from 20-27 May, the reported deaths from heatstroke were only 76," he added. 

He explained that many older and weaker people actually die in the hospital a few days after the heatwave because their organs such as kidneys, heart or lungs are impacted by the rising temperature.  

To capture the real picture, it is important to look at all causes of deaths – not only heatstroke. 

"So, when we did that, we found that within one week, around 800 additional deaths happened – in comparison to the year before and the year after," he said.

Four key strategies and  concerted efforts by agencies to save lives 

The key actions of this plan had four elements, including early warning system and inter-agency emergency response plan, public awareness and community outreach, building capacity of health staff and facilities, reducing heat exposure and promoting adaptive measures such as creating cooling centres, providing free drinking water etc. 

"We looked at the mortality rate and temperature average and then decided on three cut offs, considering Ahmedabad's dry heat. The first cut off is at 41° C which is yellow alert, 43° C is orange and 45° C is red alert," he said. 

When an alert is issued, different government agencies, for example the water department, electricity department, school authorities etc sit and strategise their respective action.

Before summer arrives, they conduct interviews of public representatives in each department on their preparedness. They also monitor, adapt and adjust the action plan each year, based on the changing scenarios and necessities. 

There are different advisories in place for different scenarios. On a hot day, anybody who has to go out has to take precautions, such as working only during early morning and evening.  

Those working outside must carry enough drinking water with them, along with a headgear to protect them from the direct sun. 

 "These are some of the simple measures that poor people can afford. And when there is a red alert, the city authority orders construction projects to not let their employees do strenuous work," he said.  

The schools also maintain their summer vacation schedules according to the change in temperature. Summer vacations begin from 9 April till 9 June, covering most of the summer period. 

Building forests and cool roofs to lower the temperature 

Neighbourhoods with densely packed buildings and no trees tend to have 6°C higher temperatures. For them, the action plan has developed more than 40 urban 'Miyawaki forests', which reduces the temperature and increases oxygen in the air. 

This method actually helps build a city forest in just 20 to 30 years, whereas regular forests can take 200 to 300 years to grow. 

In the Miyawaki method, different kinds of trees are planted closely together. This way, they only get sunlight from above, so they grow upwards, instead of spreading sideways. 

Besides planting trees, another long-term solution to beat the heat in Ahmedabad is promoting cool roofs. The roof is painted with a white reflective colour, which reduces the temperature of the house. 

The Ahmedabad Municipal Corporation formally introduced a cool roof initiative as part of the 2017 Heat Action Plan. They now have a policy in place for new buildings to come with these roofs. 

According to an article by the Natural Resources Defense Council, cool roofs are highly reflective surfaces that stay cool in the sun by minimising heat absorption and emitting most of the absorbed heat. 

Studies have shown that these surfaces can be up to 30°C cooler than conventional roof surfaces, and thereby, can reduce the indoor temperatures by 3-5°C.

"When implemented on a large scale, cool roofs can reduce the urban heat island effect in a city and lower the energy bills of the entire city. Cool roofs include coatings and treatments such as lime-based whitewash, white tarp, white china mosaic tiles and acrylic resin coating, and provide an affordable solution for providing thermal comfort," the article reads. 

Professor Mavalankar is not sure how much the project of planting 10 lakh trees per year is paying off, but according to him, the cool roof project is definitely making a change. 

There is an NGO which is working on installing cool roofs for slum dwellers. Companies also have brought forth paints that will prevent cracks on the roof where the water slips through, and also act as a reflective barrier for the heat.  

"This method could be more appropriate in Bangladesh as there is a lot of rainfall. So, there's some commercial spin off from this sole effort," Mavalankar said, adding, "we also procured jute bags from the market and put them on the metal roofs of the poor. If there is water available, sprinkling water on the jute bags will act like a cool roof. There are many simple solutions like this. Some people even put dry grass on the roof." 

Planning for the long-term is essential 

The humidity makes the heat worse, as all of us have been experiencing in the last few days. It can also lead to breathing difficulties, as I faced suddenly one night.  

I immediately checked the oximeter and found the oxygen level to be normal. And then I checked the weather. 

It was around 3 am and Google said the temperature was around 34 °C with a whopping 87% humidity. 

If you calculate this figure on the index calculator on the internet, the Heat Index Temperature will stand at 56°C with a red warning: at this condition, heat stroke is imminent. 

Pointing to Bangladesh's humidity, Professor Mavalankar said that suppose the temperature is 38°C but the humidity is 90%, then the chances of heatstroke will become higher.  

When humidity is high, your sweat doesn't evaporate and your body doesn't cool down. Why? Because on humid days, when the air is already saturated with water, sweat evaporates more slowly, explaining why it feels so much hotter during periods of higher humidity.

"In case of cyclones or floods, it is easier to get a number for the missing or dead people. But in heat waves, deaths are insidious - you cannot easily get the number. Suppose 100 people died, but you get only 10% of registered deaths," he said. 

The workers who are occupationally exposed to direct sunlight must take periodic rest, he advised. If necessary, they should work for one hour and take an hour of rest. And if the heat is higher, they should work for half an hour and rest for half an hour. "What you can do in 32°C, you cannot do in 42°C." 

He also asked people here to consider little details, such as women wearing black burkhas. 

"Black burkha absorbs more heat. But if you wear a white burkha, it will reflect more heat. So, these types of guidelines should also be given."   

Climate change is not going to be reversed in the next 80 years; the heatwaves are here to stay.  

"If you are breaking a 50-year heat record now, next year you will break a 100-year record. Every year, it is going to be hotter and hotter globally. As a nation, the message is, you have to take heat very seriously and start making localised and national heat related actions. Plan for the long-term," he said. 

"Heat will continue to be a major issue for the poor, especially because the rich will have access to water and air-conditioning. If they don't go outside one day, their livelihood will not be impacted. But poor people will starve. So, we should also talk about inequity in heat exposure," Professor Dileep Mavalankar concluded.