BEIJING • China's capital city has issued the first heat alert for the summer, after the maximum temperature in the area surged above 40 deg C.

In accordance with the orange alert issued yesterday - only the red alert comes higher on the scale - workers who are exposed to high temperatures must cut down on their working hours, according to the Xinhua news agency.

The Beijing Meteorological Service predicts that temperatures will reach 38 deg C in the lowlands of the north-eastern city today and tomorrow.

It blamed the conditions on the lack of rain.

The searing heat has triggered heavy pollution, which has clouded most roads, the China News Service reported. Visibility was limited to 2m yesterday morning.

Meanwhile, the Beijing fire department warned residents yesterday to be on high alert for gas leaks following a liquid petroleum gas explosion at a restaurant that injured one person.

Temperatures are expected to drop significantly on Wednesday, according to the Beijing Meteorological Service.

In south-western China, residents are desperately looking for ways to battle the summer heat. With temperatures hitting 35 deg C in Sichuan province, in cities such as Chengdu, Suining and Rongcheng, many have decided to cool off in the pool.

The sweltering heat drove some 8,000 people to seek refuge at the Daying Dead Sea resort in Suining last Saturday, turning its swimming pools into "massive sardine cans", according to local media.

Temperatures in Sichuan are expected to go down today as rains descend on Rongcheng.