Summer conditions South Asian countries arrive with shocking fear every year, and it is April. Most parts of India and Pakistan are already stuffy under heat wave conditions, and what scientists call it quickly becomes the "new normal."

Temperatures in the region usually rise to May, peaking in June before the monsoon brings relief. But this year the calories are already very early. “In terms of Asia and the Indian subcontinent, the transition from a brief window of spring to a summer-like heat,” said GP Sharma, president of weather at Skymet, India’s leading private forecaster.

South Asia, with a population of 1.9 billion, is particularly vulnerable. Many people live in areas with high exposure to extreme heat and lack the opportunity to obtain basic cooling, health care or water.

According to the platform that tracks extreme weather events, in Delhi, spring usually provides a brief temperature mass, with thermometers exceeding 40c in April (up to 5c above the seasonal average).

It said the "dangerous" heat seen in recent weeks should be blamed on "artificially driven climate change."

"These spring heat waves are not abnormal. They need to move beyond consciousness," said Gianmarco Mengaldo, a climate expert at the National University of Singapore and co-author of the report.

Delhi authorities urged schools to cancel their afternoon meeting on Tuesday and issue emergency guidelines to ensure water breaks and stocks of oral rehydration salts in first aid kits and to treat any signs of heat stress immediately.

The temperature in Jaipur, the capital of Jaipur, hit 44C, triggering stroke reports from construction workers and farmers. Other states are also fighting strong heat.

India's Meteorological Department reported that "heat wave days are higher than normal". Temperatures are expected to rise steadily on the subcontinent, with the highest readings on Wednesday and Thursday.

Pakistan is rolling up too. In the city of Shaheed Benaheed Benazirabad in Sindh, mercury soared to 50C, up 8.5 degrees Celsius from the April average. In other parts of the country, temperatures hover in their 40s.

"What once considered rare has become shocking because climate change accelerates the frequency and severity of such events," said the country "is still not ready for the escalating climate crisis".

The heat of the city makes the situation worse. Comparing data from 1950–1986 to 1987–2023 shows that cities such as Delhi and Islamabad are now on average 3C higher than nearby rural areas.

“When it comes to heat waves, the problem is no longer a climate change-related issue, but a threshold we want to reach,” Bangor said. “Preparation is essential. But now, our infrastructure is not well adapted.”

Natural climate change (such as the El Niño cycle) may affect regional weather, but is now in a neutral stage.

"Similar meteorological conditions now produce temperatures up to 4C compared to levels before 1986, almost entirely due to anthropogenic climate change," Clem said.

South Asia is not alone. "In the spring of the Northern Hemisphere, we have seen parts of the Middle East that are incompatible with human life," Bangor said.

"This is very serious for the crowd ... We also expect summer temperatures in Spain and France to reach unprecedented levels in the coming years," he said. "Many events that predict 2050 or 2070 are already happening. We underestimate the rate of change. What we are seeing now is acceleration - the failure of our prediction model."

David Faranda, senior climate scientist with co-author of the French National Center for Scientific Research, said: "The only sustainable solution is to stop burning fossil fuels and reduce emissions. In the absence of substantially reducing emissions and by better reducing climate resilience through better insulation, use of green energy, and other actions, the implications are stunning."

"Even if we act now, the climate system will take decades (sometimes over a century) to calm down," Bangor added. "Sea level rise has been locked in for hundreds of years."

Both researchers stressed that economic inequality and infrastructure are crucial in determining who survives extreme calories. "There are different temperature thresholds - actual temperature, (humidity index), etc.," Bangor said. "The economic level plays an important role in how people cope and maintain themselves."

Delhi has updated its hot action plan with a focus on vulnerable groups such as older people, construction workers and street vendors. But implementation is inconsistent.

Faranda said adaptability is becoming increasingly unaffordable for many countries that are prone to heat, and the grid buckles and causes widespread cuts. “When multiple events occur, you usually don’t escape,” he said.

Bangordeau highlighted the need for innovation: “We need to isolate well-housing, materials that prevent energy loss, and architectural designs that promote natural cooling. These can greatly reduce energy demand during extremely high heat.”

Flander also said that people must change their lifestyle. “Energy demand has been increasing. If we want to survive in the coming decades, we must not only build more renewable energy, but also reduce energy consumption: through lifestyle changes, efficient buildings and better materials.”