More have been hospitalized and thousands of cattle have died, as this winter's longest cold snap continues to worsen in northern Vietnam.
The cold spell, which began on January 3, continued to worsen as temperatures plunged to new lows.
Record lows in many provinces were broken on Wednesday (January 12), according to the National Center for Hydro-Meteorological Forecasting (NCHMF).
The temperature of the Mau Son Mountain in Lang Son Province, for example, reached minus 3.6 degrees Celsius compared to the previous low of 0 degrees Celsius in 1973, NCHMF's director Bui Minh Tang said.
Frost continued to cover the tops of the 1,541-meter high mountain, Tang said, adding that frost was also reported in other provinces like Lao Cai and Cao Bang.
Temperatures ranged from 2 to 5 degrees Celsius in mountainous localities. In Hanoi and other delta provinces they sank to between 7-9 degrees Celsius.
NCHMF forecast that the third cold snap to hit northern Vietnam this winter could last until January 21.
In the meantime, the National Institute of Geriatrics reported Wednesday that the number of people admitted to the hospital recently rose by between 20-30 percent, mainly with diseases like pneumonia and stroke.
Hanoi's Emergency Transport Center 115 also reported an increase of some 20 percent in emergency cases. Ambulance calls have averaged between 60 and 70 cases per day as opposed to the average of 50.
Patients are mainly elderly individuals suffering from ailments like cardiovascular disease, pneumonia, and hypertension.
Dr. Pham Manh Hung from the National Cardiovascular Institute said cold partly increases blood pressure and that people with cardiovascular diseases are easily affected by abnormal weather events.
As the cold spell continued to get worse, tens of thousands of students stayed home, in Hanoi and other provinces.
Nguyen Van Dong, chief of Lao Cai Province's Department of Education and Training's office, said that since the spell began, many students have stopped attending school. When temperatures reached their record low on Wednesday, all local schools were closed down.
The cold spell has also killed 4,219 cattle in the highland localities, according to Nguyen Thanh Son, deputy chief of the Department of Animal Husbandry.