17 Oct

Heat Waves

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Contents

• Definition
• IMD Criteria for heat waves
• Impact of Heatwaves
• NDMA’s revised guidelines for prevention and management of Heat waves in India
• Other Steps taken

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Definition

A heat wave is a period of abnormally high temperatures, more than the normal maximum temperature that occurs during the summer season usually in the north-western parts of India. In India, heat waves typically occur between March and June, and in some rare cases extend till July.

Indian Meteorological Department (IMD) criteria for heat waves.

• • Maximum Temperature of at least 40 degree Celsius for Plains, 37 degrees Celsius for coastal regions and at least 30 degree Celsius for hilly regions.
• Following conditions are used declare heat waves:

a. Based on Departure from Normal

• Heat Wave: Departure from normal is 4.5 degree to 6.4 degree.
• Severe Heat Wave: Departure from normal is > 6.4 degree.

b. Based on Actual Maximum Temperature (for plains only)

• Heat Wave: When actual maximum temperature >= 45 degree Celsius
• Severe Heat Wave: When actual maximum temperature >= 47 degree Celsius.

Increasing cases of Heat Waves in India: According to Lancet Report, India faced 60 million heatwave exposure events in 2016, a rise from 40 million exposures in 2012. Similarly, the average length of heat waves in India ranged from 3-4 days, which is more than double of global average of 0.8 – 1.8 days. The key factors responsible for this are:

Climate change -> higher temperatures

• According to a report by UNICEF “The Coldest year of the Rest of Their Lives” – nearly every child will face frequent heatwaves by 2050.

Sparser Pre-Monsoon shower and Delayed Monsoon

• This whether pattern coupled with El-Nino effect, which often increases temperature in Asia, combine to create the record high temperatures.

The Loo (hot and dry winds) originating from Pakistan and Northwest India, has also contributed to increasing temperature in India.
Urbanization and its problems like Urban Heat Island (UHI) Effect exacerbates the problem of heat wave in many parts of our country.
Decreasing Tree Covers -> concrete jungles, land heats up more.

Impact of Heatwaves

• Health Impacts – The heat waves are associated with increased rate of heat stress and heat stroke, worsening heart failures and acute kidney injury from dehydration. – Children, elderlies and those with pre-existing morbidities are particularly vulnerable. – According the NDMA, more than 24,000 people have died in India due to heat waves between 1992-2015.
•  Economic Loss – According to Lancet, the output of workforce in India declined by 7%, equivalent to 75 billion labor hours every year.
• Worsening of air pollution problems -> increased electricity use -> more fuel burned.

Steps Taken So Far

• The IMD has regularly issued heat wave warnings in different parts of the country to make people aware of the worsening situation.
• The NDMA has suggested things like covering of head, cross-ventilating rooms and sleeping under a slightly wet sheet.

NDMA’s revised guidelines for prevention and management of Heat Waves in India

Aim/Objective – The guideline aims to provide framework for developing Heat Action Plans for implementation, inter-agency coordination and impact evaluation of heat wave response activities in cities/towns.

• Developing a Heat-wave Plans
  • Generating heat wave risk and vulnerability map and mapping hotspots for developing a strategic mitigation action plan. 
  • Identifying Vulnerable Population – elderlies, pregnant women, chronic disease patient, resident of a particular type of housing, certain type of occupations etc. 
  • Identification and Evaluation of factors leading to disproportionate increase in temperature in the city.
  • Reducing Temperature in the cities through vertical gardens, small parks with water fountains etc.
  • Coordinate with Research institutions for better built environment.
  • Government budget should allocate funds for R&D in this field
  • Curb Future UHI manifestation by incorporating findings from the built environment assessment
  • Adhere to city building codes.
  • Preparedness at the local level for health eventualities.
  • Health care system capacity building
  • Collaboration with private and Non-Government and Civil Society.
  • Establish Early Warning System and Communication Systems
  • Developing inter-agency response plan and coordination in the field.

• Other Steps that can be taken:

  • Preparedness: Already discussed with NDMA guidelines
  • Response: – Ensuring quick advanced communication and guidelines during heatwave condition. – Drinking water supply should be increased along the roadside during heatwave conditions – Health facilities should respond with all the relevant facilities.
• Other steps: –
  • Reviewing the existing occupational health standards, labor laws, and sector regulation for worker’s safety.
    • Special focus on farm laborers as the agricultural sector was more vulnerable compared to the industrial and service sectors because workers there were more likely to be exposed to heat. 
  • Increased work on amenities like increased access to drinking water, indoor ventilation, healthcare, regular work breaks, and protection against wage loss.
  • Promoting more greenery throughout the city especially on both sides of the roads to ensure cooler roads.
  • Making communities more aware and resilient to after effects of the heatwaves. 
  • Internationally, the global community should work towards achieving the climate change mitigation goals by working towards Paris Climate targets and making the NDCs more ambitious.

PRELIMS UNDERSTANDING: WHAT IS HEAT STROKE?  A heat stroke happens when the ambient temperature is so high that the body’s cooling mechanism (sweating) is not able to bring down the temperature of the core. The body temperature may shoot upto 40
degree C. In these situations there is severe imbalance of salts such as sodium and potassium in the body. – The high core temperature coupled with salt imbalances disrupts the organs, leading to host of symptoms.

• It can affect the brain, making a person foggy, drowsy, and in severe cases may also lead to a person going into a coma.
• It can also lead to kidney and liver damage as well. A cascade of such symptoms may also lead to death due to heat stroke.

What should be done during such situations:

• In severe cases, the aim is to bring down the core temperature of the body fast. This can be done by pouring cold water over the person, making them drink cold drinks, and giving them electrolytes to balance salt levels.
  ▫ Visit hospitals quickly if they are exhibiting symptoms like high body temperature, but no sweat, feeling drowsy, vomiting, not passing urine, and not breathing properly.

How to prevent heat stroke?

• Don’t go out between 12 noon – 3 pm. Avoid strenuous activities during this period.
• If you have stepped out, ensure that you are drinking water even if you don’t feel thirsty. Drink other hydrating fluids, like Lassi, lemon water, buttermilk, or ORS that can maintain electrolytes levels.
• Don’t consume coffee, tea, and carbonated drinks as they by dehydrate your further.
• Wear light weight, light-colored, loose, and porous cotton clothes.

Example Questions

• What are heat waves? Suggest a strategy to reduce India’s vulnerability to heatwaves. [15 marks, 250 words]
• With a focus on the Oct 2019 guidelines from the National Disaster Management Authority (NDMA), discuss the mechanisms for preparedness to deal with Heat Waves in India. [15 marks, 250 words]
• Heatwaves can pose economic challenges to various sectors. Evaluate the economic consequences of heatwaves on industries such as agriculture, tourism, and energy, and suggest some measures to minimize their adverse effects [15 marks, 250 words]