Dangers of scorching heat in summer

A man washes his face with cold water at the Dhaka University area during the severe heatwaveFile photo

The April had turned out to be the hottest month in the country's history. The temperature was 2 degrees above the normal temperature in the month. Rain has reduced by 66 per cent. It rained in some parts of the country in the first week of May, but the heat did not ease during the daytime. A heat wave has started sweeping over the country again ahead of monsoon. Climatologists apprehended that the summer heat in Bangladesh is spiralling from a hazard to a catastrophe.

Researchers say that if someone stays in extreme heat for six hours at a stretch, it can cause long-term damage to internal organs such as kidneys, lungs and the liver. A person can even die from heatstroke.

According to two recent studies, summer has become dangerous for people in the entire South Asia, including Bangladesh. The number of hottest days of this season is increasing rapidly. Overall, 66 per cent of people in South Asia are at risk of Wet Bulb Globe Temperatures. The number of such days in summer has been increasing by one to three days per decade between 1979 and 2021. Among these, the temperature increased the most in the south-eastern region of Bangladesh.

If the temperature in an area reaches up to 35 degree Celsius and it lasts for six hours, then such a condition is called extreme heat.

According to the study, 37.5 per cent of people in rural areas of Bangladesh are at risk of extreme heat during summer. And among the cities of South Asia, this danger is soaring in Dhaka. Around 5.3 million people go outside for work during summer. The residents of the villages and cities are at high health risk due to extremely hot weather.

In such a situation, researchers have recommended planting trees, installing water taps in different parts of the city, creating green parks in each area and preserving wetlands.

ASM Maksud Kamal, head of the research team working on the impact of temperature in Bangladesh and professor of Disaster Science and Climate Resilience Department of Dhaka University, told Prothom Alo, "For so long we used to talk about cyclones and floods as disasters in Bangladesh. As a result, all our preparations and plans for disaster management centered on those two disasters. But like lightning, summer heat is turning into a slow onset disaster for us. We only care more about the temperature in the city. But in big cities like Dhaka as well as the agricultural population of the rural areas has to work in the open land amid the heat. As a result, they are also at risk of that heat. We have to think about controlling the temperature in rural areas as well as in urban areas.”

Explaining extreme heat

According to the study, in the early 1960s, US soldiers used to fall sick while training in the heat. US scientists for the first time tried to understand the suffering and risk of people in the heat. Beside high temperatures, they take into account humidity, wind flow, timespan for an area keeping hot, and the direction of the sun rays. Collectively, all those weather conditions are combined to create an indicator called the wet bulb globe temperature. They started using the indicator to understand how much a person is exposed to that heat and how they are affected by it.

Later, the impact on construction workers and poor people from other parts of Asia who went to work in the Middle East came to the fore. The issue of rising temperature has been included in the state policy in the East Asian countries including Australia, Thailand and Indonesia. This temperature issue is brought to the forecast and observation separately from the meteorological department of the countries.

This year, a study has been conducted about the threat of extreme hot weather for the first time in South Asia. The study report was published in the international scientific journal Sustainable Cities and Society last March. The study titled 'Spatiotemporal Changes in Population Exposure to Heat Stress in South Asia' examines the extent to which South Asians are exposed to heat stress and its temporal and spatial effects.

Associate professors Shamsuddin Shahid and Aung Kyaw Kyaw of the University of Technology in Malaysia, Mohammed Magdy Hamed, a researcher at the Arab Academy for Sciences in Egypt, and Mohammad Kamruzzaman, a senior scientist at the Bangladesh Rice Research Institute, conducted the research jointly.

According to the study, 1.7 million people in South Asia are exposed to excess heat every year. At different times such temperature is increasing in densely populated areas of Bangladesh, Pakistan and India. Along with the increase in the average temperature of the whole world, the intensity of heat has increased drastically due to climate change.

Shamsuddin Shahid, who is associated with the two studies, said, "In many countries of the world, rising heat during summer is a major threat to public health. We have not yet acknowledged that risk in Bangladesh. The topic came to discussion recently. In many countries around the world, infrastructure facilities are being enhanced along with advice and forecasting to deal with such situations. It includes planting adequate trees along roads, installing water taps, conserving reservoirs and creating green parks in every area. We should follow that as well.”

Where the temperature of Bangladesh heading?

Professor Maksud Kamal of Dhaka University and associate professor Shamsuddin Shahid and Abul Kashem Faruqi Fahim of University Technology Malaysia jointly conducted the study on the effects of extreme heat in Bangladesh. The study titled 'Changes in Wet Bulb Globe Temperature and Risk to Heat Related Hazard: An Overview of Bangladesh' is in the process of being published in an international science journal.

One of the members of the research team, a senior scientist of Bangladesh Rice Research Institute Md Kamruzzaman told Prothom Alo that agricultural workers and day labourers in urban areas are most at risk due to such heat. They should be provided with advice and support on accurate forecasting and what to do in such situations. Otherwise this excess heat will turn into a major disaster for a large number of people in the country.

What is the Meteorological Department doing?

The Bangladesh Meteorological Department usually provides forecasts and observations for the public on their website, but does not contain any information about extreme temperatures. They mainly measure the temperature, the percentage of humidity in the air and the length of sun exposure and release this information separately. However, some researchers of the organisation said that they are trying to understand the wet bulb globe temperature.

Global meteorological research organisations including AccuWeather, Weather OnGround, Windy provide temperature measurements for most parts of the world. And weather agencies in the United States and many countries in Europe also predict very hot temperatures separately so that citizens can have idea as to where, when and how long such weather will persist.

Meteorologist Shameem Hassan Bhuiyan of the meteorological department told Prothom Alo, "We have heard about the work that Dhaka University has done jointly with some famous universities of the world regarding the temperature. I hadn’t the opportunity to check it yet. We are also researching on extreme temperature in Bangladesh. We will be able to make that forecast if we get assistance from the universities.”

*This report, originally published in Prothom Alo print edition, has been rewritten in English by Farjana Liakat