Central Weather Bureau officials said the public should wear extra clothing and stay warm after at least 28 people throughout the country have died during the recent cold snap.
Daytime temperatures on Thursday were between 11oC and 12oC for most of the northern region.
A cold air mass from China also led to plunging temperatures in southern Taiwan.
According to reports, there have been 14 incidents of sudden death in relation to the cold. They occurred in Taipei, New Taipei City (新北市) and Keelung on Thursday, with the sudden drop in temperatures inducing heart attacks and other cardiovascular conditions in elderly people.
In Taoyuan County, four deaths were reported, which were attributed to the cold weather of the past two days.
A homeless man in Greater Taichung was reported to have suffered a heart attack and died on Wednesday, and two similar cases were reported in Chiayi City, with officials attributing the cause of the cardiac arrests to the cold snap.
Doctors at Fongyuan Hospital in Greater Taichung said they treated seven patients in the emergency room on Thursday, mostly due to cardiovascular strokes.
All of them were treated and were recovering, the doctors said, adding that normally they only receive one or two such cases in a day.
A fire department official in Greater Tainan said on Thursday that seven individuals had died Wednesday and Thursday as result of cardiac arrest, adding that the fire department also received numerous calls over situations in which elderly people required medical treatment due to the cold.
Pai Hui-wen (白惠文), a doctor of geriatric medicine in Chiayi City, said blood vessels will constrict in cold weather, which pushes up blood pressure.
“Elderly people tend not to drink enough water, due to an aversion to going to the bathroom during sleeping hours. This can raise blood viscosity, leading to reduced blood flow, and can result in myocardial infarction or stroke,” Pai said.
“Senior citizens with high blood pressure and diabetes must take their regular medication and drink warm water during the winter,” he added.