Poor localities in the northern highlands region have been hit hard by the prolonged and harsh cold weather since early this month.
However, it has not stoped locals, including children, from going out and working in almost freezing temperatures to earn a living.
The mercury in Lao Cai province has dipped as low as 0 degrees Celsius with frost covering many local mountains.
However, Hau A Sinh, an eighth-grader in Y Ty Commune, located at the height of 2,000 meters above sea level, still climbed the Can Cau hill to pick leaves for his family's pig and buffalo wearing only a thin coat.
His face cracked and purple by the cold, Sinh said his family had not gone out for the last two days, so their buffalo and pig didn't get anything to eat.
"It's still very cold today, but I had to wake up early to pick leaves for the animals, or they'll die," the boy said.
Since the cold spell worsened a couple of days ago, all the students in Y Ty have been allowed to stay at home, but Sinh, who is the breadwinner of his family, had to go out to work.
Sinh said his father died when he was nine months old, and his mother married again, leaving his elder brother and Sinh to fend for themselves. So, he has to work to support his brother who suffers from a liver disease. Every day, after school, he goes to work on a field which is large enough to yield just four kilograms of rice.
Hau A Lanh, Sinh's brother, said: "It's so cold at this time, so we suffer hunger every year. ["¦] It's so cold but Sinh has to go to the forest without proper coats; it can't be helped, because we are too poor."
To protect the buffalo, the most precious property of his family, Sinh even gave away his only blanket to keep it warm.
Sinh is not the only one in the village.
Vu Van Thanh, vice principal of Y Ty Secondary School, said although students were allowed to stay at home due to the cold weather, many of them still followed their parents to forests or fields to work.
They are all going out in thin coats almost torn after several years of use, he said.
While all schools have been closed, teachers still work, going everywhere to ask for blankets and coats for their students, they said. And whenever they get something, they would walk to students' villages to give it to them.
However, even when students get more coats to protect themselves from the cold, going to forests these days still involves the risk of stumbling and falling due to fog and exhaustion.
The nurse at the commune health center said local residents hve been hospitalized recently not only with cold-related diseases but other injuries.
Trang A Lu, chairman of Y Ty's People's Committee, said all they can do is to advise local people, especially children, to stay at home, and avoid the cold.
"But, cattle and pigs are hungry, if they stay at home too long, plus firewood will run out, so they end up going to the forest regardless of the cold," Lu said.
Since it began on January 3, the cold snap, which set a record low temperature of minus 3.6 degrees Celsius on Tuesday (January 11) in Lang Son province, has killed nearly 4,200 cattle across the northern region, according to the Department of Animal Husbandry.
The National Center for Hydro-Meteorological Forecasting said the spell would last until January 21.