ISLAMABAD, Pakistan — Muslims from around the world are in the Saudi city of Mecca for the Hajj, one of the Five Pillars of Islam.
In the coming days, people will immerse themselves in religious rituals and acts of worship that originated more than 1,400 years ago.
They also have to contend with excess heat and other earthly factors, like a ban on children under the age of 12 and a crackdown on unauthorized entry.
Here's what to know about this year's Hajj:
Beating the heat in the Saudi desert
Last year's pilgrims struggled through burning sun and suffocating hot weather, with the mercury hitting 47 degrees Celsius (117 degrees Fahrenheit). More than 1,300 people died.
This year, Saudi authorities are advising caution in direct sunlight, telling pilgrims to avoid going out during the day and uncovering their heads, except for rituals, unless necessary.
An official safety kit emphasizes the importance of light-colored clothing and umbrellas. It also has details on recognizing and treating the symptoms of dehydration and heat exhaustion.