Walkers pass by a tricycle loaded with bottled water in Beijing, July 12. The high temperatures also caused heavy ozone pollution, according to the city's environmental watchdog. [Photo/Chinanews.com]

A heat wave pushed temperatures to above 40 C in some northern and central parts of China on Monday.

The China Meteorological Administration said temperatures hit 35 C in 14 provinces and municipalities, while parts of North China recorded temperatures of 41 C. The hot weather will continue until Wednesday.

The heat wave also worsened the severe drought in northern China, which has received just half of its normal rainfall since June, said Yin Xiaohui, chief forecaster at the Beijing Meteorological Center.

The surface water area of Miyun Reservoir, one of Beijing's major sources of water, has shrunk nearly 40 percent during the past year, Xinhua News Agency reported.

The heat wave arrived in northern and central China on Sunday, with the National Meteorological Center issuing a yellow alert for high temperatures in central, eastern and northern China. A yellow alert was also issued on Monday.

Under the four-tier, color-coded weather warning system, red represents the most severe weather, followed by orange, yellow and blue.

Most parts of Beijing experienced temperatures of up to 39 C on Monday, with 42.2 C recorded in the central urban area, according to the Beijing Meteorological Bureau.

Thunderstorms may hit Beijing on Tuesday, and temperatures are expected to fall to 30 C by Wednesday.

The bureau has warned people to pay attention to fire risks and advised those working outdoors to take measures to avoid heatstroke.

Guo Qiang, an express deliveryman in Beijing, said high temperatures in the past two days have made riding his motorized tricycle more difficult.

"Sometimes I feel a little dizzy under the baking sun," he said.

Guo said he still has to work for more than 10 hours a day despite the hot weather.

"But I will find an office building with air conditioning to rest in for a while if I feel too hot," he said.

Hu Jianbao, a garbage collector in Beijing, said the summer heat in the city forces him to extend his working hours.

"I am usually cautious about the risk of heatstroke. I start work around 5 am every day, reduce my working hours around midday and work late into the evening," Hu said.

"Avoiding exposure to direct sunlight at noon is my way to cope with the heat, which means I don't finish work before 10 pm, later than in other seasons," he added.

Thunderstorms are Hu's biggest worry during the summer months. He carries the garbage on his electric-powered tricycle to a trash station for recycling.

"When a thunderstorm comes, I have to cover the waste because it becomes worthless when it gets wet. It is also too hot for me to wear a raincoat while riding. I get a fever sometimes when I am caught in the rain," he said.

Zheng Jinran contributed to this story.

Contact the writers through wangxiaodong@chinadaily.com.cn