Thousands of World Cup stadium workers in Qatar have been handed "cooling vests" to help them cope with building tournament venues in the desert country's extreme temperatures.

The Supreme Committee for Delivery and Legacy, Qatar's World Cup organizers, said the "state-of-the-art" vests can reduce the wearer's body temperatures by up to 15 degrees Celsius.

"The cooling vest has the potential to transform the lives of our workers," said Mahmoud Qutub, a workers' welfare executive with the committee, in a statement posted on its website.

They have been developed in conjunction with a British-based cooling technology company, TechNiche.

The dayglo vests work after being submerged in water.

The water is then soaked up by a polymer fiber within the vest, said the committee.

As the water evaporates airflows built into the vest cool down the wearer.

The fabric "holds the water layer for slow evaporation over several hours, delivering constant cooling," read the statement.

Organizers say 3,500 vests have so far been given to workers such as steel fixers, carpenters and scaffolders.

Currently there are almost 26,000 workers helping build or refurbish Qatar's eight proposed stadiums.

Qatar has sought to improve conditions for the construction workers in response to a Human Rights Watch report claiming fierce temperatures could threaten thousands of their lives.

Thursday is the final day of summer working restrictions in Qatar, which saw laborers prevented from working outside from 11:30 a.m. to 3 p.m. from June 15.

Although that restriction ends on Sept. 1, forecasts for the first few days of next month estimate temperatures will be around the 40 degrees Celsius mark (104 Fahrenheit).

When it won the right to host the 2022 World Cup, Qatar initially was set to host the tournament during its summer.

It was shifted by FIFA to be played in November and December 2022, as a summer tournament in the Gulf was seen as unworkable, despite organizers promising air-conditioned stadiums.