Assessment of heat stress change in Hanoi city

Hanoi is the second-largest city in Vietnam, with rapid urbanization, high population density and continuously increasing people's income. However, due to climate change and urbanization, heat stress is becoming more and more serious, affecting public health. This study used the method of calculating effective temperature (ET) to evaluate the spatial and temporal variation of heat stress in Hanoi city from the period 1961 to 2020. Calculation results of the ET value showed that the ET at the hot and fairly hot level was mainly concentrated in June, July, and August. ET tends to increase markedly over time. During the period 1961 - 1997, there was almost no hot ET, but from 1998 to the present, the number of hot ET months occurs frequently in June and July. The number of hot months in the downtown area of Hanoi is much higher than in the surrounding areas. With such a trend in the future, the months of June and July will always have hot ET. The research results are useful documents for management agencies and the health sector to take specific actions to strengthen the health care system, develop infrastructure, and inform the community about the risk of heat stress.