What is heat wave and does India have a strategy to deal with it? Know here

Here is all you need to know about heat wave and what should be the preventive measures.

Do you know that before 2015, heat waves were not notified as a natural disaster at the national level, though between 1992 to 2015 as per official records nearly 24,223 lost their lives due to the same?

As Northern India prepares to face intense heat waves in the next few days as predicted by the India Meteorological Department (IMD) , the following is your guide to the weather event and what should be the preventive measures.

What’s the scare?

IMD in a forecast made on Monday said that heat wave conditions are expected to start over Central and Northwest India from April 27.

As a prelude to the same, maximum temperatures were recorded between 40-42 degrees Celsius over most parts of Rajasthan, Madhya Pradesh, eastern Uttar Pradesh, Bihar, Gujarat, Vidarbha, Odisha and Gangetic West Bengal; in some parts of Haryana and Delhi, Chhattisgarh, Jharkhand and in isolated pockets over Madhya Maharashtra, Marathwada, Telangana and Rayalaseema on Sunday.

The weather office said a gradual rise in maximum temperatures by 2-3 degrees Celsius can be expected over most parts of Northwest during the next three days (starting from April 27)—a situation that is expected to continue with “no large change thereafter”.

Also, a gradual rise in maximum temperatures by 2-4 degrees Celsius will also be seen over Madhya Pradesh and Maharashtra and in Gujarat by 2-3 degrees Celsius during the next four days.

So what exactly is a heat wave?

The IMD qualitatively classifies a heat wave as one when the air temperature becomes fatal to the human body when exposed. And, quantitatively it is defined based on temperature thresholds over a region in terms of actual temperature or its departure from normal.

So what are those thresholds?

Heat wave is considered if the maximum temperature of a station (a meteorological centre) reaches at least 40 degrees Celsius or more in plains and 30 degrees Celsius or more in the hills.

Also, heat waves generally occur, in the months of March to June and in some rare cases even in July.

The peak month of the heat wave over India is May. But, this year, due to the advancement of summer, the peak heat wave month itself seems to have also advanced.

So, what are the heat wave prone states in India?

Heat waves generally occur over plains of northwest India, Central, East and north Peninsular India.

It covers the states of Punjab, Haryana, Delhi, Uttar Pradesh, Bihar, Jharkhand, West Bengal, Odisha, Madhya Pradesh, Rajasthan, Gujarat, parts of Maharashtra & Karnataka, Andhra Pradesh and Telangana. Sometimes it occurs over Tamil Nadu and Kerala as well.

Is the frequency of heat waves rising?

The IMD and National Disaster Management Authority (NDMA) chronicle that in 2015, around nine states were impacted by heat waves.

While in 2020, as many as 23 states have been impacted by heat waves, a 156 per cent jump.

The World Meteorological Organization's 2020 statement on global climate indicates that global temperatures will continue to increase.

The years 2015, 2016, 2017, 2018 and 2019 have been confirmed as the five warmest years on record. In 2019, unlike in earlier years, even night temperatures were high.

Does India have a strategy to deal with heat waves?

Believe it or not, before 2015, there wasn’t any national level comprehensive strategy to fight heat waves.

As per the NDMA, before 2015, the primary responsibility for disaster risk management rested with the state governments.

Chhattisgarh, Odisha, Kerala, Rajasthan, Andhra Pradesh, Maharashtra and Karnataka had declared heat waves as a local disaster.

Heat waves were not notified as a disaster at the national level under the existing disaster relief policies.

But, state governments were authorised to spend up to 10 per cent of funds under certain heads for heat wave relief.

Surprisingly, this was despite the fact that the biggest casualties of heat wave conditions were mostly the poor and vulnerable in the unorganised sectors, such as daily-wage labourers, street hawkers, etc.

They are compelled to work outdoors out of economic necessity, to earn their livelihood. Being unable to avoid the outdoors, they are particularly vulnerable to the dangers of heat wave conditions.

So what changed after 2015?

After 2015, the natural disaster started figuring in the priority list of topmost officials in the country including the Prime Minister as chairman of the NDMA.

Following which in 2016, the NDMA drew up the first national guidelines for heat waves titled 'Preparation of Action Plan–Prevention and Management of Heat Wave'.

The guidelines were twice revised, first in 2017 and then in 2019. They were enriched with recommendations for more specific actions, based on scientific inputs derived from various research papers, reports and best practices in heat wave assessment and mapping techniques.

The ward level Heat Action Plans have improved the capacities of cities and states in managing heat stress and meeting heat wave related emergencies.

The revisions in 2019 included a new section, 'Built Environment'; the revisions focused on short-term, medium-term and long-term measures for heat wave risk reduction.

So what do the guidelines have?

The National Guidelines on Heat Wave clearly mentions the roles and responsibilities of the central and state government agencies, district administrations, local self-governments, NGOs, civil society organisations and other stakeholders in a matrix format.

So what has been the progress in building a foolproof disaster management plan against heat waves?

A NDMA document says that between 2015 and 2019, 17 heat wave prone states prepared their Heat Wave Action Plans and more than 120 districts or cities from14 states have also prepared their own Action Plans.

These plans help the state governments to develop measures and strategies for heat wave assessment, forecast, preparedness and mitigation through coordinated efforts with multiple agencies.

“In this way, states and local authorities are able to undertake long-term mitigation measures to reduce the negative impacts of heat-wave conditions,” the NDMA document said.

The NDMA also conducted a preliminary study to estimate the temperature threshold for 103 cities in India for heat wave conditions, and the resulting report was released in September 2019.

The objective of this study was to determine preliminary thresholds of the lower level of the maximum temperature beyond which there was a noticeable increase in all-cause mortality.

Have some other measures also initiated for dealing with heat waves?

Over the years, the NDMA has also taken host of measures that include rescheduling of working hours for outdoor workers, creation of drinking water kiosks, supply of water through tankers, erection of special shelter homes, increase in health facilities, stocking of ORS packets at health centres and the nearest anganwadi centres, placement of cooling systems and construction of gaushalas with fodder banks, etc

Is violation of the guidelines punishable?

In normal circumstances, they aren’t unless implemented under any act.

Have the steps shown any result?

The government claims that because of the aggressive measures taken to deal with heat waves both by the Centre and states, deaths due to heat waves have dropped from from 2,040 in 2015 to just 4 in 2020.

So what are broad SOPs to deal with heat waves?

The NDMA lists some common steps on how to face heat waves but there are district specific and region-wise specific strategies as well. These include

• Drink sufficient water and as often as possible, even if not thirsty.
• Wear lightweight, light-colored, loose, and porous cotton clothes. Use protective goggles, umbrella/hat, shoes or chappals while going out in the sun.
• While travelling, carry water with you.
• If you work outside, use a hat or an umbrella and also use a damp cloth on your head, neck, face and limbs.
• Use ORS, homemade drinks like lassi, torani (rice water), lemon water, buttermilk, etc. which help to re-hydrate the body.
• Recognise the signs of heat stroke, heat rash or heat cramps such as weakness, dizziness, headache, nausea, sweating and seizures. If you feel faint or ill, see a doctor immediately.
• Keep animals in shade and give them plenty of water to drink.
• Keep your home cool, use curtains, shutters or sunshade and open windows at night.
• Use fans, damp clothing and take bath in cold water frequently.
• Provide cool drinking water near work place.
• Caution workers to avoid direct sunlight.
• Schedule strenuous jobs to cooler times of the day.
• Increasing the frequency and length of rest breaks for outdoor activities.
• Pregnant workers and workers with a medical condition should be given additional attention.