Wang Lu, a head worker, said heatstroke prevention suits were issued to the workers to keep them safe. They were also given mosquito repellent and sunscreen cream.

After a day of working in high temperatures, the employees return to their dormitories, where mung bean soup is prepared to help them cool down, Wang added.

Delivery drivers also endure long spells of exposure to heat. In Harbin, capital of Heilongjiang province, their employer, the food delivery platform Eleme, reduces the risks they face.

Li Bo, director of the logistics department at Eleme's branch in Heilongjiang, said: "We have issued thousands of packs against heatstroke to our food delivery workers across Harbin. The packs include a pair of sun-shading sleeves, a bottle of water, a waterproof bag and mosquito repellent.

"During the extremely hot weather on Sunday and Monday, we set up water supply points at 35 stations throughout the city. Cold bottled water, ice cream, cooling ointment and other materials were prepared for our workers."

Drones are being used in Harbin to detect electrical equipment overheating, helping reduce the need for human inspections.

Operated by the State Grid Harbin Power Supply Co, the drones capture images of specific areas and upload them to a digital platform, where they are examined for possible equipment malfunctions.

The drones can inspect an electric power line spanning 2 kilometers in just 30 minutes, the company said in a statement.

Contact the writers at lilei@chinadaily.com.cn