As El Nino is forecast to intensify and persist through the end of the year, experts have warned people not to underestimate the health impacts of extreme weather, particularly on the cardiovascular system.
Heatwaves are affecting many localities nationwide, with temperatures commonly ranging from 36 to 40 degrees Celsius and even higher in some areas.
In recent days, northern and central provinces have experienced a widespread heatwave. In Hanoi, outdoor temperatures have reached 39–40 degrees Celsius at various times of the day. Heat absorbed by asphalt roads and concrete structures has made urban areas even more uncomfortable, especially around midday and early afternoon.
In central Vietnam, temperatures exceeding 38 degrees Celsius have continued to be recorded. Outdoor workers, including construction labourers, delivery drivers, ride-hailing drivers and farmers, are among those most directly exposed to harsh weather conditions.
According to Mai Van Khiem, Director of the National Center for Hydro-Meteorological Forecasting, El Nino has emerged and is continuing to strengthen. The phenomenon is expected to last until the end of 2026 and may extend into the early months of 2027.
The likelihood of El Nino reaching a very strong intensity has increased to around 60–65 percent by the end of this year and early next year. Under its influence, the number of hot days this year is forecast to exceed the long-term average and be higher than in 2025, although it is unlikely to surpass the records set in 2024.
Experts noted that in urban areas, the “heat island” effect caused by concrete surfaces, asphalt roads and dense construction can make perceived temperatures 2–4 degrees Celsius higher than official readings. Combined with low humidity and intense ultraviolet radiation, these conditions accelerate dehydration and increase the risk of heat exhaustion and other health problems.
Doctor Do Doan Bach of the Vietnam National Heart Institute at Bach Mai Hospital said high temperatures force the body to activate cooling mechanisms, including blood vessel dilation, increased sweating and circulatory system activity. The loss of water and electrolytes through perspiration makes the heart work harder and may alter blood pressure and heart rhythms, increasing the risk of cardiovascular events or worsening existing heart conditions.
Particular caution is advised for the elderly, people with hypertension, coronary artery disease, heart failure or arrhythmia, those taking diuretics or cardiovascular medications, and individuals who work outdoors for extended periods.
Doctor Do Doan Bach warned against common mistakes during hot weather, such as drinking water only when feeling thirsty, working continuously under direct sunlight without adequate rest, or moving abruptly between air-conditioned environments and extreme outdoor heat. Patients with cardiovascular diseases should also avoid adjusting medication dosages without consulting their doctors.
Experts recommended drinking water regularly, limiting prolonged exposure to extreme heat, wearing light and breathable clothing, and seeking shade whenever possible. People should seek immediate medical attention if they experience symptoms such as chest pain, shortness of breath, persistent dizziness, rapid heartbeat, severe headache, fainting or confusion.
With El Nino expected to intensify and heatwaves likely to continue, proactive health protection measures are essential to minimise the risks posed by extreme weather conditions.
