Public hospital chief Tony Ko on Saturday urged people who get sick but with mild symptoms to seek help from private doctors instead of from emergency rooms in the next few days.
Writing on his blog, the chief executive of the Hospital Authority said he is very worried about emergency rooms being inundated and long waiting times over the holiday period.
Ko said emergency rooms had been receiving nearly 5,000 people a day recently, and the Hospital Authority expects that number to rise further during the current cold snap.
"And as many private doctors would take time off these few days, we are very worried about public hospital emergency rooms getting even busier," he wrote.
He also expressed concern over a rise in Covid-19 clusters at elderly care homes in recent weeks.
He said public hospitals have been under huge pressure treating an increasing number of people who felt ill because of the cold weather and Covid-19.
Ko said the Hospital Authority has rearranged manpower to cope with the demand, and thanked staff working over the festive season.