URUMQI, July 23 -- A record heat wave continued to scorch northwest China's Xinjiang Uygur Autonomous Region on Thursday, forcing people to stay indoors and leaving air conditioners out of stock in shopping centers.

The 10 hottest cities in China were all in Xinjiang on Wednesday. The maximum temperature in most cities was above 37 degrees Celsius, according to the Central Meteorological Station.

Turpan Prefecture, also known as "Fire State," topped the chart with temperature reaching 46 degrees Celsius on Thursday. The maximum temperature there has remained above 45 degrees Celsius since July 15.

The surface temperature at a highway toll station was as high as 69 degrees Celsius, according to Hua Feng, a Turpan traffic police officer.

"The soles of my shoes cracked due to the heat after being on duty for six hours, even though I stood under a shade," said Hua.

Locals have to compete for air conditioners in shopping malls in Urumqi, the regional capital, as the record heat wave has hit the city for 10 days.

The number of patients with cardiovascular diseases, often triggered by sunstroke, almost doubled to 20 on Wednesday at the regional hospital of traditional Chinese medicine, said Jiao Quanlin, a doctor from its emergency department.

The heat is expected to last until Sunday, according to the regional meteorological station.

The station warned of risks of flood and landslides brought by melting snow in mountainous areas.