People enjoy themselves in a water park in Shanghai to drive away summer heat. The city experienced a record-high temperature of 40.6 degrees Celsius on July 26. [Photo/Xinhua]

Doctors are warning the elderly and those with a weak constitution to stay in air-conditioned rooms as electric fans are insufficient to keep people cool in such hot temperatures.

Some hospitals in the city received more than 15,000 patients each yesterday, an unusually big number. A sharp rise in patients is being seen in dermatology, respiratory and pediatric departments.

Xinhua Hospital is opening for registrations at 6am compared to the usual 7:30am and is also adding services at night to cope with the increased numbers of people seeking help.

The Shanghai Rescue Station said it had received an average of 41 homeless people a day this month, a 10 percent rise compared to January to June.

The rest of the country is also sizzling. By yesterday, 19 provinces and cities in China, or about a third of the country's territory, were experiencing high-temperature days.

Many cities in Hunan Province also endured record high temperatures this month. The provincial capital Changsha reported temperatures at or above 35 degrees Celsius in all of the past 29 days.

The province received over 70 percent less rain than normal, leaving 33 counties and cities suffering severe drought.

Hot weather in the week ahead, when temperatures could rise to 41 degrees in Hunan's central and eastern parts, could worsen the drought situation, the provincial forecasters said.

Turpan City in the Xinjiang Uygur Autonomous Region recorded a high of 44.3 degrees yesterday, making it the country's hottest city.