Pedestrians hold umbrellas as sun shade in Beijing, capital of China, May 22, 2019. Beijing's observatory issued a yellow alert on May 21 for high temperatures over the remainder of the week. (Xinhua/Zhang Chenlin)

SHIJIAZHUANG, July 4 (Xinhua) -- Residents have been advised to guard against the heat wave as north China's Hebei Province issued a red alert for high temperatures Wednesday.

Temperatures could rise to 37 to 40 degrees Celsius in central and southern parts of the province on Thursday, according to the provincial observatory.

As of 11 a.m. on Thursday, 17 cities and counties in the province have issued a red alert for high temperatures.

The observatory advised that workers exposed to high temperatures should take protective measures.

China has a four-tier color-coded weather warning system, with red representing the most severe, followed by orange, yellow and blue.