These Indian cities experiencing life-threatening heatwaves

According to the India Meteorological Department, some regions in Bihar and West Bengal had continuous heatwaves for 19 and 17 days, respectively, in June.

Odisha, coastal Andhra Pradesh, Jharkhand, and Chhattisgarh also saw 9 - 14 hot days in June.

During this time, temperatures in Bihar and West Bengal ranged from 50 to 60 degrees Celsius. (PTI)

During this period, Bihar had temperatures ranging from 50 to 60 degrees Celsius. West Bengal would have experienced the same heat index readings since meteorological factors such as late monsoon and a high humidity level were similar for both places. According to experts, the circumstances were lethal, with the possibility of death of hundreds of thousands of individuals with vulnerabilities.

Despite the slightly lesser frequency of scorching temperatures in April and May shifting attention away from extreme heat in the country, climate scientists cautioned June's high heat in eastern India should be regarded as a warning.

"From May 30 to June 22, Bihar faced a heat crisis. The highest maximum temperature of 45.3 ° S was recorded in the Bhojpur district and the surrounding area of Arrah. The heatwave pockets had highest temperatures between 40 to 45 degrees, with humidity varied from 37% to 47%," said Ananda Shankar, a scientist from the weather bureau's Bihar office. 

The highest temperature of 40 degrees with 47% humidity means a so-called "feels like" temperature or a heat index of 53 degrees; a maximum temperature of 45 degrees with 37% humidity translates to a heat index of 60 degrees, according to the US National Oceanic and Atmospheric Administration's heat index calculator.

The Met Department reported 218 days of heatwaves across the country from March to June. After 2019, with 578 days of this kind, following 2022, with 455 days, it was the greatest in the previous 23 years. The month with the most heatwave days was June, with regions of eastern India seeing 11 to 19 heatwave days.

The combination of sustained heat, high day temperatures, and high humidity caused a heat stress tragedy. "Other than the magnitude of heat and humidity, the duration of heatwaves is an important component in heatstroke-related mortality," stated Roxy Mathew Koll of the Indian Institute of Tropical Meteorology. " Being exposed is a major risk factor that we often overlook when considering health," as per experts.

"There are two kinds of heat stroke that are fatal." The first is what is known as exertional heat stroke. For example, suppose a person is working in direct sunlight and becomes extremely hot and nauseous before suffering from a heat stroke. This is known as exertional heat stroke death. Such incidents account for around 10% of all heat-related deaths. "The remaining 90% of fatalities are due to indirect heat stroke or non-exertional heat stroke," said Dr. Dileep Mavalankar, director of the Indian Institute of Public Health in Gandhinagar.

"During a heat wave, a person becomes extremely heated." As a result, the heart needs to circulate more blood to the skin to cool the body through sweat, which leads to heart failure in an aged and sick individual. Kidneys can fail if they are dehydrated. If the internal body temperature rises above 40 degrees Celsius, proteins begin to break, leading to the failure of various organs such as the kidneys, brain, liver, and heart.

Due to sweating, the body may be cold and clammy when touched in this situation, making identifying challenging as long as the internal temperature is examined. Consider someone living in a tin-roofed home on a hot day when the temperature inside is similar to that of a furnace. Likewise, the core body temperature could be extremely high. However, cold water sponging or an ice pack should be used as an urgent remedy. The temperature of the rectum is not always tested in India, although it is the only technique to determine core body temperature and the impact of heat," he added.

Extreme temperatures have killed more individuals in India than any other natural disaster to protect tropical cyclones, according to a report released in April by the weather department. It utilized data from 1961 to 2020 to figure out heatwave climatology and occurrence. On average, more than two heatwaves occur throughout northern areas of the country, as well as coastal Andhra Pradesh and Odisha. In some areas, the frequency of heat waves reaches 4 every season. The majority of official meteorological stations show rising trends in heatwave duration, frequency, and severity over 60 years.

The matter would continue to get uglier. The duration and severity of hot days and nights are expected to grow throughout India in the years to come, while cold days and nights are predicted to go down, according to a 2020 report from the earth sciences ministry. According to the analysis, the frequency, length, intensity, and area coverage of pre-monsoon season scorching temperatures over India are expected to grow significantly this century.

As a result, doctors rarely connect deaths completely to heat strokes because they are frequently a contributing factor. Hyperthermia can result in reduced or increased blood circulation, failure of the organs, and fatality. "It's impossible to say with certainty that heat caused deaths," Shankar says.

Considering this, there are methods for estimating how many individuals died as a result of the scorching temperatures. "First, we have to figure out whether there was an increase in mortality. In Ahmedabad, for example, we discovered that the average everyday fatality rate is 100 in May. During heatwaves, we observed an increase in excess mortality of 310 deaths, a total of 210 deaths. So, first and foremost, it is critical to determine the mortality rate per 1,000 population and whether there are any excess fatalities. Although there are no excess deaths, we need to understand the reasons and the impact of heat," said Dr Mavlankar.

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