All outdoor work will have to stop during the hottest part of the day in the UAE, Saudi Arabia.
A ban on working outside during the hottest part of the day – when temperatures can reach 50 degrees Celsius – has started in several Gulf states on Sunday.
In the UAE, the stop-work applies between 12.30pm and 3pm, while in Saudi Arabia the ban starts at 12pm.
It affects mostly construction workers. Oil and gas companies and any emergency maintenance work are exempt, although businesses are expected to take precautions from the sun.
The ban will continue until September 15.
In Bahrain it runs only during July and August, although there have been calls for it to be extended to include June because of rising temperatures earlier in the season.
Authorities are expected to conduct inspections throughout the summer to ensure employers comply with the rules.
It is the tenth year the ban has applied in the UAE.
Last week, the Labour Ministry urged business owners to provide shaded areas for the workers during their break period and to completely cease work.
It warned that violators will be fined AED15,000 ($4,083), if found forcing labourers to work under direct sunlight, adding that if a large number of workers are affected, the company might face temporary suspension from operations.