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Rising Heat Stress and its Mitigation

GS Paper 3 (Heat Stress and its Mitigation)

 Syllabus: Disaster management/ Geography

 Context: Rising Heat-Stress temperatures in urban India are not solely due to climate change but also a result of increased concretization and urban sprawl, contributing to excess heat stress.

India’s major cities, including Delhi, Mumbai, Chennai, Bengaluru, Kolkata, and Hyderabad, are facing worsening heat stress due to excess heat relative humidity over the past two decades and increasing Urban Heat Island Effect, according to a study by the Centre for Science and Environment.


What is Heat stress?

It occurs when the body cannot effectively release excess heat, leading to a rise in core temperature and increased heart rate. It’s a physiological strain experienced in high-temperature environments. Causes include high ambient temperatures, humidity, physical exertion, inadequate hydration, and poor ventilation. Symptoms include difficulty concentrating, irritability, sickness, and loss of thirst, progressing to fainting and potentially death if not cooled down.

What other factors exacerbate Heat Stress?

In major Indian cities, heat stress is exacerbated by factors such as air and land surface temperature, relative humidity, and rapid urbanization with increased concretization. Climate change has worsened heat waves by raising temperatures and humidity levels. Additionally, changes in land use and urban sprawl contribute to the “urban heat island effect,” trapping heat in city centres. This poses a significant risk to vulnerable groups like the elderly, infants, pregnant women, slum dwellers, and outdoor workers.

According to the World Health Organisation heat stress linked to climate change is likely to cause 38,000 extra deaths a year worldwide between 2030 and 2050.


What is the Urban Heat Island Effect?

The Urban Heat Island (UHI) effect describes urban areas experiencing higher temperatures than rural surroundings due to human activities and urban characteristics. Causes include surface materials like asphalt and concrete, heat from industrial processes and vehicles, reduced vegetation, building density, and waste heat.


Impact of heat stress/heat waves:

  • On Human Health:
  1. Heat-related illnesses: Heat waves can cause heat exhaustion, cramps, and stroke, which can lead to dehydration, fatigue, and even death.
  2. Exacerbation of existing conditions: People with existing health conditions such as respiratory diseases and cardiovascular diseases are more vulnerable during heat waves.
  3. Mental health: Excess heat waves can also impact mental health, causing stress, anxiety, and other mental health issues.
  4. Affected Regions: Southern Asia and western Africa are expected to be the hardest hit, with approximately 5% of working hours lost by 2030. India could lose 5.8% of its working hours, affecting 34 million jobs, mainly in agriculture and construction.
  5. Social Consequences: Heat stress may deepen inequality between low and high-income countries, worsen conditions for vulnerable workers, and lead to increased migration as people seek better opportunities, impacting both men and women in agriculture and construction.


  • On Environment:
  1. Water resources: Heat waves can lead to droughts, reducing the availability of water resources for agriculture and domestic use.
  2. Wildlife: High temperature can impact wildlife, leading to habitat loss and increased mortality rates.
  3. Air quality: Heat waves can worsen air quality, leading to respiratory issues and other health problems.


  • On Economy:
  1. Economic Loss: Heat stress may cost the global economy $2.4 trillion annually, with a projected 2% loss in total working hours worldwide.
  2. Affected Sectors: Agriculture, particularly for women, and construction will suffer the most, with an estimated 60% and 19% loss in working hours by 2030, respectively.
  3. Agriculture: High temperature can impact crop yields and agricultural productivity, leading to economic losses for farmers and the agricultural industry.
  4. Energy consumption: Heat waves can lead to increased energy consumption as people use more air conditioning and other cooling systems.
  5. Tourism: Heat waves can impact the tourism industry, leading to decreased revenues for businesses that rely on tourism.


Measures Already Taken for Heat Stress:

  1. National Level: The Indian government has launched a National Action Plan on Climate Change, which includes measures to address heat waves and other climate-related issues.
    1. National Action Plan for Climate Change (NAPCC): Includes 8 national missions focusing on various aspects of climate change mitigation and adaptation.
    2. India Cooling Action Plan (ICAP): Aims to reduce cooling demand by 20-25% and refrigeration demand by 25-30% by 2037.
    3. NDMA Guidelines: Comprehensive guidelines issued in 2016 by the National Disaster Management Authority for mitigating the impact of heatwaves.
  2. State and City Level: Many state governments and city administrations have taken measures such as opening cooling shelters, distributing free drinking water, and implementing heat wave warning systems.
  3. Civil Society Organizations (CSOs): Several CSOs are working to raise awareness about the impacts of heat waves and provide support to vulnerable communities.

Measures that Need to be Taken for Heat Stress:

  1. Heatwave preparedness: There is a need for excess heat-wave preparedness, including the development of early warning systems and emergency response plans. g. Heatwave early warning systems
  2. Urban planning: Urban planning should focus on designing cities that are more resilient to heat waves, such as increasing green cover and promoting the use of reflective materials. e.g. urban high temperature preparedness plans
  3. Sustainable agriculture: There is a need for sustainable agricultural practices that are more resilient to heat waves, such as crop diversification and better water management.
  4. Community engagement: There is a need for community engagement and awareness-raising activities to ensure that vulnerable populations are aware of the risks of high temperature and can take necessary precautions.
  5. Green infrastructure: India can promote the use of green infrastructure, such as green roofs and urban green spaces, green transport which can help to reduce the heat island effect in cities and lower temperatures.
  6. Climate resilient infrastructure: E.g. heat-resistant buildings and water conservation measures
  7. Policies and Guidelines: Develop weather variability and urban heat management policies.
  8. Public Awareness: Educate people about heatwave risks and reducing carbon footprint.
  9. Agricultural Adaptation: Support farmers with resilient farming practices
  10. Disaster Management: Develop emergency response plans and cool shelters.
  11. Short-term Measures: Establish an early warning system and integrate it with public health services.
  12. Long-term Measures: Implement structural infrastructure changes for  adaptation.



Heat waves are a serious threat to human health, the environment, and the economy. While some measures have already been taken to mitigate their impacts, more needs to be done to ensure that vulnerable populations are protected and that the country is better prepared for future heat waves.


What is a Heatwave?

The IMD says a heatwave is considered when the maximum temperature of a station touches at least 40 degrees Celsius or more for plains, 37 degrees Celsius or more for coastal regions and at least 30 degrees Celsius or more for hilly regions. A ‘Heatwave’ is declared when the departure from normal temperature is by 4.5 to 6.4 degrees Celsius and a ‘severe heatwave’ is when the departure from normal is more than 6.4 degrees Celsius.

Extreme Heat Waves and Mitigation img
Rising Heat Waves and its Mitigation

Insta Links:

 Heat stroke

Source: IE

Mains Links:

Q: Bring out the causes for the formation of heat islands in the urban habitat of the world.