Countries across Asia have been hit by another round of extreme heat that has toppled seasonal temperature records throughout the region, raising concerns about their ability to adapt to a rapidly changing climate.
After punishing heatwaves struck large parts of the continent in April, temperatures spiked again in late May, normally the start of the cooler monsoon season.
Seasonal highs were registered in China, southeast Asia and elsewhere, and experts warned that there was more to come.
"We can't say that these are events that we need to get used to, and adapt to, and mitigate against, because they are only going to get worse as climate change progresses," said Sarah Perkins-Kirkpatrick, a climate scientist with the University of New South Wales in Australia.
The heatwave in Vietnam, expected to last well into June, has already forced authorities to turn off street lights and ration electricity as air conditioning demand threatened to overwhelm the power grid.
The country recorded its highest temperature ever on May 6, at 44.1 Celsius (111.4 Fahrenheit), in Thanh Hoa province, about 150 km (93 miles) south of Hanoi. Another province came close to the record on Wednesday, hitting 43.3C.
Vietnam's national weather forecaster warned on Thursday of residential fire risks due to high power consumption. With temperatures set to range from 35C and 39C in the coming two days, it also warned of the risks of dehydration, exhaustion and heat strokes.
India, Pakistan and southeast Asia already experienced a punishing heatwave in April, causing widespread infrastructure damage and a surge in heat stroke cases. Bangladesh was also at its hottest in 50 years, while Thailand hit a record 45C.
Seasonal temperature records also continued to tumble through May, with steamy Singapore at its hottest for the month in 40 years.
The April heatwave was "30 times more likely" because of climate change, a team of climate researchers said last month, and the current temperature spike "is likely to be caused by the same factors," said Chaya Vaddhanaphuti from Thailand's Chiang Mai University, who was part of the team.
India and other countries have established protocols to deal with the health risks arising from extreme heat, opening up public "cool rooms" and imposing restrictions on outdoor work, but Vaddhanaphuti said governments need to plan better, especially to protect more vulnerable communities.
Researchers from the University of Bristol warned in a paper published in April that regions with little prior experience of extreme heat could be most at risk, identifying eastern Russia as well as the Chinese capital Beijing and surrounding districts among the more vulnerable.
But for countries like India, where humidity is already pushing "wet bulb" temperatures to unsafe levels, preparing for the worst might not be enough, said Vikki Thompson, the paper's lead author.
"At some point we get to the limit of humans actually being able to cope with the temperatures," she said. "There could be a point where nobody could cope with them."
As many as 2 billion people will be exposed to dangerous heat if the world remains on its current track to rise an average 2.7C this century, with India likely to be the worst hit, scientists warned in another study published last week.
