Dire warnings: More deadly heat waves, more often, which could cause more deaths

Heat Waves and the need for immediate action

Heat wave warnings are dire - picture showing a summer afternoon by the coast
Though many cities have had a Heat Action Plan has been in place since 2019, the most vulnerable people rarely receive alerts on potential health hazards and remain unaware of what they should do in an emergency. Pic Pixabay

When Prime Minister Narendra Modi returned to Delhi on May 5th after a three day soak in pleasant European clime, the weather in the national capital was way better than when he had left. Yet, among the first things he did was hold a high level meeting where he instructed officials to take steps that would avert deaths due to heat waves and fire incidents.

But one swallow does not a summer make. Those pleasant hours after some showers, high speed winds, and lowering of temperature, did not signal the end of the heat wave in the National Capital Region. That very day, the Indian Meteorological Department (IMD) predicted that a fresh spell of heat wave conditions were likely to commence over Northwest India from May 7, and over Central India from May 8. (March this year was the hottest in 122 years. And during all those 122 years, April has been warmer than this year just twice. While the last few days has seen temperatures in Delhi cross 47 degrees celsius).

The Intergovernmental Panel on Climate Change (IPCC) says it is “very likely” that heat waves in the 21st century will be hotter, longer and more frequent”. Maximum temperature records that in the past were broken once in 20 years, will now be broken every other year, said the IPCC report.


Read more: Heat wave information: What to look out for and where?


All this simply means heat waves will now be a seasonal occurrence, and people will have to learn to adapt and live with it.

“As the world’s third largest emitter of carbon dioxide, India is extremely vulnerable to the impacts of climate change, including more deadly heat waves and cyclones”, says Natural Resources Defense Council (NRDC), a group of law students and attorneys who have been at the forefront of the environmental movement since it was formed way back in 1970.

Credited with developing South Asia’s first early-warning system regarding extreme heat, NRDC coordinated with public health officials and the city administration to develop the Ahmedabad Heat Action Plan. More than 100 other cities across 23 states have now based their alert systems on this document which is intended to protect the most vulnerable, primarily those who work outdoors.

In the summer of 2010, when Ahmedabad scorched at over 46 degrees C, hospitals and municipal authorities were overwhelmed with cases identified as having been caused by heat wave. That was perhaps the first time they were linking outside extreme temperature with health. A year later, they realised the high temperatures were also proving fatal.

The first Heat Action Plan

Comparing the death rates during May in 2009, ’10 and ’11, experts compared the impact of extreme temperature on gross mortality. During the heatwave of 2010, number of deaths rose from the usual average of 100 deaths to 310 in Ahmedabad alone. Across the state, there were 1344 more deaths representing a 43% increase in gross mortality in May of that year.

One fallout from this was that the IMD starting issuing seven-day forecast, with colour coded warning system that indicated expected intensity of heat, implemented as the Ahmedabad Heat Action Plan in 2013.

The health department became the lead agency, and media, mobile companies, NGOs, all were involved. People were told to carry an oral rehydration salt (ORS) when they stepped out. Radio and SMS alerts particularly helped create public awareness: stay indoors, stay hydrated, cover your head.

Most importantly, hospitals were trained to be prepared to receive and deal with heat-related emergency illnesses.

Three years later, in 2016, 10 cities had similar Heat Action Plans. Since 2019, over a 100 cities including Delhi have them. The IMD now provides a five-day city specific summer forecast.

Delhi’s State Action Plan on Climate Change, for instance, details measures to prepare for heat waves, almost along the lines of the Graded Action Plan (GRAP) to respond to air pollution. But while GRAP addresses larger target groups—like industry, motor-vehicles, users of diesel gen sets—for which the Delhi government in conjunction with the Delhi Disaster Management Authority issues instructions, the Delhi Pollution Control Committee mandated to issue alerts on heat waves is yet to get active.

Health impact

Over the years, there have been many studies on the relationship between heat waves and health.

“Heat waves have several health impacts—dehydration, heat cramps, heat exhaustion and/or heat stroke,” writes Dr Ramnath Jha, a Distinguished Fellow at the Observer Research Foundation, Mumbai, in his issue brief on “Extreme Heat Events in India’s Cities: A Framework for Adaptive Action Plans” of January 2021.

“Heat cramps result in edema (swelling) and syncope (fainting), often accompanied by fever. Heat exhaustion can cause fatigue, weakness, dizziness, headaches, nausea, vomiting, muscle cramps and sweating. Heat strokes can cause body temperature to rise to 40°C (104°F) or more and can result in delirium, seizures, coma or possible fatality”.


Read more: “Our system issues daily warnings about impending heat waves”: Mrityunjay Mohapatra, Director General, IMD


Stating that heat waves killed about 6,187 people in India between 2011 and 2018, Jha says that data on heat wave fatalities are not widely available since most cases go unreported and the ambiguity of symptoms may mean that mortality rates are not accurately captured.

The reality however is that though cities in north India have had a Heat Action Plan has been in place since 2019, the most vulnerable people, who mostly do not have the luxury of staying indoors and have poor access even to the bare minimum requirement of potable water, rarely receive alerts on potential health hazards and remain unaware of what they should do in an emergency.

Representational image for a hot summer day
File pic. The Intergovernmental Panel on Climate Change (IPCC) says it is “very likely” that heat waves in the 21st century will be hotter, longer and more frequent” and that maximum temperature records that in the past were broken once in 20 years, will now be broken every other year. Pic Pixahive

Predictable and preventable

The Delhi Pollution Control Committee which was to issue the alerts said a new plan was prepared but the pandemic came in the way.

Heat is a predictable and preventable disaster, believes the NRDC. Which is why the National Disaster Management Plan 2019 deals with heat waves in detail, from pages 207 to 218. But states and their district administrations have yet to implement the guidelines.

The simplest one is the state government having “heat treatment wings” in hospitals. Even if this were simplified to say reserve a few beds for heat stroke patients, hospitals not only don’t have such reservation, but a couple of hospitals I talked to had no clue about such a guideline. “We can provide beds for such patients if they come through the Emergency,” said a doctor in an East Delhi hospital.

One of the medium term responsibilities the NDMA Plan 2019 mentions is to implement a system of heat alerts to trigger early morning shifts for schools and offices, rescheduling school and office timings during the heat wave season, and to construct shelters, bus stands, etc that offer shelter from heat wave.

While none of these has ever been implemented, these days it is hard to find even shade-giving trees in areas where the mass of people work.

Dr Jha moots the proposal of a national Heat Action Plan. “Given India’s increasing vulnerability to heat waves, it must first recognise such incidents as a disaster to make national and state disaster assistance available for mitigation efforts. A national HAP will be extremely beneficial to cities and will drive a national agenda to embed adaptation planning for rising temperature in our plans and design for space, utilities, infrastructure and industries.” says Dr Jha.

Among his other suggestions for cities are:

  • Promoting urban forestry. 
  • Building water bodies and fountains in dense areas, and improving green transport and energy systems 
  • Avoiding unnecessary concretisation and encouraging maximum permeability in construction.
  • Cities will have to introduce building plans that ensure inhabitants are protected from extreme temperatures. 
  • Building bylaws should include components on passive ventilation and cool-roof technologies to increase thermal comfort. Investments will need to be directed towards clean technologies and low carbon development.

But despite all the data, reports, warnings and suggestions, seriously mitigating all the adverse effects of heat waves on health and economy remain a low priority item for decision makers.

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About Vijaya Pushkarna 60 Articles
Vijaya Pushkarna is a journalist based in New Delhi. She was formerly Deputy Bureau Chief, Delhi at The Week.