For the third time this summer, China's most populous city of Shanghai issued its highest alert for extreme heat as sweltering temperatures repeatedly tested records this week.
The commercial and industrial hub of 25 million people declared a red alert on Thursday, warning of expected temperatures of at least 40 degrees C (104 F) in the next 24 hours.
Temperatures soared as high as 40.6 C in the afternoon, but fell short of Wednesday's 40.9 C, which matched a 2017 record.
As of 5:00 p.m.(0900 GMT), Shanghai's red alert was in force. The highest of a three-tier colour-coded warning system, it requires construction and other outdoor work to be reduced or halted.
Shanghai has issued three red alerts in the past five days, though these are a relatively rare occurrence, with just 17 issued since record-keeping began in 1873.
The hot weather coincided with mass testing for COVID-19 in several districts amid minor outbreaks, adding to heat woes for both residents and health workers wearing protective suits.
Some COVID-19 testers taped bottles of frozen mineral water to their white hazmat suits as they worked, while others sat next to huge blocks of ice to cool off.
"This suit is terribly hot," Peng Lei, who worked at one testing site, told Reuters. "The clothes are never dry. All day long they are wet with sweat."
Some communities also began testing in the evening when it was cooler.
The past month's unusually hot spell has affected half of China. The Yangtze River basin, encompassing large cities from Shanghai to Chongqing in the heartland has broiled in heat waves over the past week.
By 5:00 p.m., 86 red alerts had been declared across China, most in the Yangtze basin.
Higher demand for air-conditioning pushed China's maximum power load to an all-time high on Tuesday.
Authorities said they were making every effort to ensure energy supplies during the summer peak demand period.
(Reporting by Albee Zhang, Xihao Jiang and Ryan Woo; Editing by Christopher Cushing and Clarence Fernandez)