As temperatures hit their highest level so far this year government departments have been urged to save energy.

The temperature rose to 36 C in the southern metropolis yesterday, with electricity consumption also closing on record levels as more and more people turned their air conditioning up.

The electric grid has been operating at full capacity in Guangzhou, according to an official from the Guangzhou Economic Commission.

And yesterday, the electric charge reached 7.2 million kilowatts, challenging the city's highest ever charge of 7.28 million kilowatts, said the official, who refused to be named.

Government departments, companies and other organizations have been told to save electricity, while some factories were urged to stop production during peak hours, the official said.

Many cities in the Pearl River Delta have also witnessed a sharp growth in electricity consumption over the past week.

Guangdong Observatory has been issuing warnings about the weather since last Thursday, with local residents and tourists urged to take measures to protect themselves from the heat.

But despite the warnings the number of people admitted to Guangzhou's hospitals with heat-related ailments has increased by more than 30 per cent in the past week.

According to a doctor from Guangzhou No 1 People's Hospital, the number of both outpatient and emergency cases has increased sharply. Other major hospitals in Guangzhou have seen similar rises.

Most patients suffer from fever, sunstroke or related acute diseases.

The heat wave has been passing over Guangdong Province since the middle of last week, with temperatures in more than 40 cities and counties in the province hitting 35 C over the past four days, according to the Guangdong Observatory.

Observatory official Huang Zhong said the scorching temperatures would last until Thursday, when heavy rain is expected.

The drought in the western part of Guangdong has become even more severe because of the hot weather, said sources from the Guangdong Provincial Bureau of Water Conservancy.

The heat wave, however, has spurred the sales of air-conditioners and electric fans across Guangzhou.

And business is also booming at karaoke bars, cinemas and shopping centres with air-conditioning.

The steamy weather is also influencing fashion, with lower collars and backless clothing becoming popular in the southern metropolis.

Editor: Yan