In 1995, when temperatures rose 0.74C, Vietnam lost 0.8 per cent of daylight working hours. In 2085, if temperatures were to rise 1.5C, 2.58 per cent of daylight working hours would be lost. If temperatures were to rise 2.4, 2.7 or 4C, Vietnam would lose 5.09, 6.31, and 12.72 per cent of daylight working hours.

“The lowest income-bracket work - heavy labor and low-skill agricultural and manufacturing jobs - are among the most susceptible to climate change,” the report noted. Factories are limited in providing cooling systems at the workplace, it added.

In November 2015 the International Labor Organization (ILO) introduced guidelines for governments and other labor organizations to address the health and safety ramifi­cations of climate change, but no international organization has established a program to assist countries vulnerable to the challenges of climate change for the workplace, according to the report.

“Actions are needed to protect workers and employers now and in the future, including low-cost measures such as assured access to drinking water in workplaces, frequent rest breaks, and management of output targets, carried out with protection of income and other conditions of Decent Work,” the report urged.

“Modeling the Impacts of Climate Change on Future Vietnamese Households”, a research working paper from the World Bank released in July said that it is not hard to imagine that if most workers work outside or without air conditioning then the impact of temperature increases on labor productivity will be stronger than if there is a fast structural change away from agriculture and towards services and industry, together with the greater prevalence of air conditioning.

As for the impact of high temperatures on labor productivity, people working outside or without air conditioning will lose between 1 and 3 per cent in labor productivity due to changes in climate compared with a baseline of no climate change, the World Bank paper said.

“Our results show that the temperature impacts of climate change are severe in the poverty scenario: 270,000 people would be pushed into poverty in 2030 and 700,000 would be pushed below $4 per day,” the paper said.

The researchers, led by Tord Kjellstrom from the Health and Environment International Trust in New Zealand, announced in July that Vietnam and 42 other countries will be affected by temperature increases.

It estimated that 5.7 per cent of Vietnam’s GDP would be impacted by rising temperatures. From 15 to 20 per cent of annual working hours in Southeast Asia have already been lost in heat-exposed jobs and this may double by 2050 as global warming continues.

Other Southeast Asian countries such as Indonesia, Thailand, the Philippines, Malaysia and Cambodia will also lose GDP due to rising temperatures. The researchers said that Indonesia and Thailand will both lose 6 per cent by 2030, the Philippines and Malaysia 5.9 per cent, and Cambodia 5.7 per cent.