Temperatures in parts of China have hit record highs, leading to the "hottest July" in Shanghai on record, state media say.
In Shanghai, at least 10 people have died from heatstroke, as the city experiences its hottest July in 140 years, reports say.
Local journalists have demonstrated the heat by frying meat on the pavement.
The national heat alert covers nine provinces, including Anhui, Jiangsu, Hunan, Hubei, Shanghai and Chongqing.
According to figures from the Shanghai Meteorological bureau, Shanghai has seen 24 days with temperatures at or above 35C in July.
More than 10 people in Shanghai have died after suffering from heatstroke, state-run news agency Xinhua said, citing health officials.
In a TV report, journalists from Shanghai TV said they successfully fried a pork chop on a marble slab outdoors in just 10 minutes.
The practice appears to have become popular, with photos of slices of bacon and fish being barbecued outdoors by the heat appearing online. ...
It added that weather forecasts suggested that some areas south of the Yangtze river, including Chongqing, could experience temperatures of over 35C until 8 August.
It urged members of the public to avoid outdoor activities and to take protective measures against the heat.