Power supply suffers while demand surges, exceeding 1.5 billion kilowatts for the first time last week, energy officials said, in a third new record for China this month, when its first nationwide alert on heat-related health risks also went out.

“High-temperature weather will… have an impact on power generation and supply,” weather official Chen Hui told a press conference today, adding that it would hit hydropower output and reduce the efficiency of photovoltaic generation.

Authorities will send alerts to notify electricity suppliers if tactics such as peak-shaving and cross-regional dispatching of power are called for, added Chen, an official of China’s meteorological administration.

Since mid-March, the number of days when temperatures hit 35°C or more is the highest on record, said Jia Xiaolong, deputy director of the national climate centre.

Authorities asked the elderly to stay indoors unless necessary, while urging outdoor workers to scale down activity on such “sauna days”.

Temperatures have hit new highs since mid-March in the central provinces of Henan and Hubei, Shandong in the east, Sichuan in the southwest, and northwestern Shaanxi and Xinjiang, pushing the national average to the second highest on record.

During the last two weeks, 152 national weather observatories tracked temperatures above 40°C with one in Xinjiang reaching 48.7°C, Jia said.

He did not rule out the chance of more record-breaking heat, saying August could prove as warm as, or even hotter than, in recent years.