The Inner Mongolia autonomous region and provinces in Northeast China, which are favorite tourist destinations for escaping summer heat, experienced an unusual heat wave, with temperatures of more than 40 C for the past two days.

But the heat is expected to ease starting from Friday, after a little rain.

Temperatures in Inner Mongolia's Hulunbuir hit a record high of 44.1 C on Wednesday. Dozens of people sought medical assistance for heatstroke. The previous record in the city, nicknamed "China's cold pole", was 42.5 C.

"The locals are experienced at dealing with extreme cold, but not the heat," said Ren Dongwei, an emergency doctor at the city's People's Hospital. "This lack of awareness may easily lead to heatstroke."

In Harbin, the capital of Heilongjiang province - often tagged as "ice city" - the temperature hit 33.7 C on Thursday.

According to the National Meteorological Center, the rare heat wave is the result of a continental high-pressure zone that controls the area. The dry air makes the temperature soar rapidly during the daytime, although it drops off swiftly again after sunset.

Inner Mongolia, especially Hulunbuir, has had a run of hot, dry weather over nearly two months, leading to droughts and locust infestations.

Liang Shuang contributed to this story.