Last Saturday, Vietnam’s experienced its hottest temperature ever in Huong Khe District, Ha Tinh Province.

A recording of 43.4 degree Celsius, or 110 degrees Fahrenheit, was the highest temperature ever recorded in the country, the Washington Post reported.

Normally, at this time of the year, temperatures in the area ranged from 27 to 32 degree Celsius.

On Tuesday, the northwest region, southern and central provinces suffered the sweltering heat of 34-37 degree Celsius temperatures, according to the National Hydro-Meteorological Forecasting Center.

In some parts of northern mountainous provinces, temperatures soared to 38 degrees Celsius.

In the capital city, Hanoians have also been struggling with temperatures of 35 to 37 degrees Celsius.

The ongoing heat wave is likely to sweep across the country until this Saturday, said Nguyen Van Huong, a senior meteorologist.

Local residents have been warned to be careful about explosions and fires. The central and northwest regions face higher risks of forest fires, experts have said.

A weak return of El Nino, which features a warming of ocean surface temperatures in the Pacific that typically occurs every few years, is expected again this summer. However, the phenomenon is unlikely to have a major impact on the weather in Vietnam, experts said.

The average temperature of summer months this year has tended to be 0.5-1 degrees higher than that of previous years, so the heat wave could push the mercury to 39-42 degrees.

Heat waves are likely to hit the northwest region in April-May, the northeastern region from May to June and the north and central regions from April to August.

The southern provinces are expected to feel the heat of 35 to 38 degrees Celsius. In HCMC, the RealFeel temperature could reach nearly 40C during summer, posing health risks.

Data from Weather Online, a U.K.-based meteorological services firm, shows the ultraviolet index in HCMC remained at the ‘extremely dangerous’ level of 12 from last Monday to Thursday, posing risks of eye damage, overheating and dehydration, especially for children and babies.

A UV Index of between 0 and 3 is considered ‘low’, and above 11 is deemed ‘extreme,’ with radiation that could burn skin and damage eyes within 30 minutes. Such high UV levels were also reported in Saigon in mid-February and late March.

For comparison, the level never exceeds 8 in the U.K. In fact it only rises to 7 in the two weeks around the summer solstice.

A study published in the journal Climatic Change last September said Southeast Asian countries like the Philippines and Vietnam would be most affected by heat-related mortality along with countries in Southern Europe and South America.

This is how the Saigonese have been coping with summer heat in recent years: