Victoria Park - a popular outdoor gathering spot for Indonesian domestic helpers on their weekly day off - was playing host to a large-scale outdoor celebration featuring popular singers from their homeland, as it has done for the past 10 years. Some of those standing in the tightly-packed crowd sought help and were taken to tents behind the main stage for first aid.

"The heat is very serious. There have always been so many people participating in the event, but I have never seen so many needing medical help," said Annie Setyo, an Indonesian who joined the party. 

"It was not as hot last year," added her friend,  Bella Aquastina.

Event organiser the Indonesian consulate finished the activities two hours early at 3pm

Chalief Akbar, Indonesia's consul general, expressed sadness that people fell ill and said organisers were caught out.

"The weather is very unpredictable. We were not expecting the weather today to be so hot," Akbar said. "Next year if this weather still occurs, we will try to get more fans for the people."

He noted that the organisers had put two intermissions in the show so people could take a rest and also distributed water to keep the crowd cool.

Weather forecaster Chan Sai-tick explained the hot weather yesterday was caused by a continental airstream from the mainland, which was dragged to the coast of Guangdong in part by Typhoon Goni, which is moving east of Taiwan.

"There was little cloud over Guangdong and the continental airstream from mainland China made the day very hot," Chan said.

A similar weather pattern saw temperatures in Hong Kong hit the highest levels ever recorded on August 8. The Observatory expects the next couple of days to remain hot and sunny.