With his three-year-old daughter suffering from rashes and himself battling insomnia due to sinusitis, Tran Huy used all his annual leave to take his family to Nghe An, escaping a prolonged period of pollution.

Fine dust, tens of times smaller than a human hair, penetrates pores, damaging the skin's natural protective layer, causing irritation and premature aging.

For nearly a week, Nguyen Thi Hien, 51, has continuously worked in toxic air, leading to frequent coughing, fatigue, and especially difficulty breathing at night.

hanoi and many northern provinces have recorded air quality index (AQI) levels exceeding 200 this winter, an emergency warning level that poses severe risks to lung and cardiovascular health.