SHANGHAI - Zhang Lanxiang, a 48-year-old street cleaner who works from 5 am to 1 pm seven days a week in the city's bustling Luwan district, finds the searing sun occasionally makes her feel dizzy.

"This time of day, around noon, is definitely the hardest, with peak traffic on the roads pushing up the temperature," said Zhang, a native of Jiangsu.

"It's really hot and there is no place to hide," she said. "I'm lucky I didn't get sunstroke."