"Hospitals are now gathered with more patients from this morning," said Tuen Mun Hospital's Deputy Hospital Chief Executive Terry Lau Chu-leung, "the cold weather, coupled with the epidemic, may trigger or exacerbate diseases of patients, especially the seniors."

Non-emergency patients may take at least seven hours to see doctors in the emergency departments at United Christian Hospital and Yan Chai Hospital, according to the 'A&E Waiting Time' on the Hospital Authority website.

Lau suggests patients with mild symptoms consider going to private or general outpatient clinics for quicker treatment.

Meanwhile, hundreds of the elderly reported feeling uncomfortable as the temperature in urban areas was recorded at 10 degrees in the morning.

"We heard 566 requests for help from the elderly by 11 am this morning, most were heart or breath sickness, and 55 of which need treatment," said Senior Citizen Home Safety Association.

More than 5,000 people asked for help in the past three days under the cold weather, according to the association.