GAZA CITY, Gaza Strip – Over a billion Muslims around the world began observing the holy month of Ramadan on Wednesday, with the dawn-to-dusk fast posing a particular challenge for the devout in the sweltering Middle East summer.

A heat wave has covered much of the region, putting even the most ardent believers to the test.

In some places — such as Egypt, Lebanon and the Gaza Strip — the hardship of abstaining from food, drink and cigarettes for 15 hours was compounded by frequent power outages.

“I’m not sure if I can continue fasting,” lamented Ismail Abu-Hasweh, 28, standing in line at a government office in Amman, Jordan. “I’m a chain smoker and I feel lightheaded because I didn’t smoke or drink my coffee,” he added, removing dark sunglasses to show his red eyes.

The start of Ramadan changes every year, based on the sighting of the new moon at the start of the lunar month.

This year, most Sunni Muslims began fasting Wednesday, while Shiite Muslims in Iran, Iraq and Oman are to begin observances today.

midday, temperatures topped 100 in many parts of the Middle East. Some took steps to ease the burden of fasting.

The governments in Jordan, Lebanon and the Palestinian territories reduced the work day of civil servants from eight to six hours. Some construction workers in Lebanon struck deals with their employers to work for a few hours at night.

In the United Arab Emirates, the top religious authority issued a religious edict, or fatwa, allowing laborers to eat if it is too hot or conditions are too difficult to fast.