Hundreds of construction workers in the capital city start their day well before dawn to avoid the sweltering heat of normal working hours. 

A group of workers for a construction project in Ha Dong District wake up every day at 3 a.m. to make it to work on time. In their makeshift, stuffy shack, they have a super early breakfast together and divide shifts between themselves before the day begins.

The workers, who came from different localities, work all day and only return to the shack to sleep at night. To cope with the summer heat, they use a mist-spraying system to cool themselves down inside the shack.

Several workers can be seen at a construction site at 4 a.m., already wearing protective gear. Their normal work schedule is from 7 a.m. to 11:30 a.m. and 2 p.m. to 5 p.m. But for the last two weeks, they have been working from 4 a.m. to 8:30 a.m. and 4 p.m. to 8:30 p.m. – an eight-hour break during the working day.

The capital city has been experiencing a severe heat wave of late, with temperatures soaring up to 40 degrees Celsius.

Bright lights are used at the construction site as workers do their heavy lifting in the predawn dark.

They are well into their work as dawn breaks.

"Last year, when the heat reached its peak, there were workers who fainted from heat strokes and had to be taken to the hospital. Learning from that experience, as this year's summer begins, we've changed working hours and taken measures to help workers avoid the heat and maintain their productivity," said Hoang Kim Thuan (R), a worker at the site.

Among the workers are many members of ethnic minority communities who normally live in highland areas where temperatures are cool throughout the year. They are particularly troubled and discomfited by the Hanoi heat.

A worker pours drinking water into a bucket of ice.

"Iced water tricks the sense of thirst, so it is an effective method to cool down at the site. The group of workers here, around 10 people, drink three buckets of water along with 15 kg of ice every day," said Thuan.

Sin Van Tan, a worker from the northern highlands province of Dien Bien, wipes his face with a cloth soaked in ice water to cool himself down after three hours of work.

A worker enjoys a smoke break, using a typical Vietnamese bamboo bong. 

At 8:30 a.m., when the heat starts to crank up, workers rest inside buildings still under construction. They use nets, intended to shield things from dust, as makeshift hammocks to lie down in before returning to work in the afternoon.