Fatshimetrie: Sweltering nights in India, a growing health danger
As summer is in full swing in India, the country is experiencing an unbearable heatwave, marked by record temperatures in New Delhi, the world’s most populous capital. The nights are becoming increasingly hot and uncomfortable, leaving little respite for a population already suffering from oppressive days.
At the heart of this furnace, an alarming reality emerges: despite the sunset, the stifling heat persists in the streets of the city. According to a recent report by the Center for Science and Environment (CSE), the temperature drops by only 8.5 degrees Celsius at night in Delhi, compared to 12.2 degrees Celsius on the urban outskirts. This nighttime heat deprives residents of the rest needed to recover from long hours of exposure to the oppressive heat, especially for those without access to air conditioning.
Street workers, such as rickshaw drivers, face increasingly difficult working conditions. Sagar Mandal, an autorickshaw rider, complains that there are fewer passengers opting for air-conditioned taxis rather than open-air transport. “My body can’t take it anymore, but I have to keep cycling. We are used to physical work, we don’t complain about that. But this heat is not normal, something has to change,” says this man from 39 years old.
Likewise, Nikhil Kumar, a tuk-tuk driver, reports increasingly long and grueling working days due to the persistent heat. “At night, the situation does not improve. Even at night, I sweat. It rained a little last night, but look how hot it is today, there is no respite,” laments this driver 26 years old.
Warmer and warmer nights: a warning of climate change
Scientists are warning of the consequences of global warming, which are reflected in particular by increasingly hot nights. Studies have shown that higher nighttime temperatures make it difficult to fall asleep and reduce the phases of deep sleep and REM sleep, which are essential for the body to regenerate during the night.
This trend is not unique to India: In the United States, for example, nights are warming faster than days in most parts of the country, according to the 2018 National Climate Assessment report.
Increased nighttime heat worsens health risks related to heat stress. Pregnant women exposed to heatwaves may experience complications such as premature delivery, while older adults may experience higher heart rates and increased physiological stress from sleeping in hotter temperatures..
Impacts on energy supplies, water and public health
The urban heat island effect, amplified in cities like Delhi, contributes to increasingly hot nights, with metropolitan areas significantly warmer than their surroundings. Paved surfaces and dense concrete buildings absorb more solar heat than green spaces and tree-lined streets.
The scorching days and nights are putting strain on the country’s power grid and water supply, and the pressure on these resources is already having health consequences. Frequent power outages deprive residents of their air conditioning system, worsening their discomfort. Additionally, the water provided once a day is boiling hot, making living conditions difficult for many Indians.
The toll is heavy: more than 40,000 cases of sunstroke have been recorded in India since March, and at least 110 deaths due to suspected sunstroke have been reported across the country. Dr Ajay Chauhan, head of the heat stroke unit at RML Hospital in Delhi, points out that warmer nights lead to increased stress on the body. When a person suffers from heatstroke, the progression of symptoms is rapid, and without early intervention, the mortality rate is very high.
In conclusion, rising night temperatures in India reflect the growing challenges posed by climate change. The adverse effects on residents’ health, combined with pressures on infrastructure and resources such as electricity and water, highlight the urgency of action to mitigate the consequences of extreme heat. Only a collective and coordinated response can protect India’s people from the ravages of a changing climate and ensure a safer and more sustainable future for all.