Muslim pilgrims pray on Mount Arafat in hajj climax

More than 1.5 million Muslims will pray on Mount Arafat in soaring temperatures on Saturday, in the high-point and most gruelling day of the annual hajj pilgrimage.

Worshippers from all over the world will climb the rocky, 70-metre (230-feet) hill, about 20 kilometres (12 miles) from Makkah, where the Prophet Mohammed is believed to have given his last sermon.

The desert summer heat is expected to hit 43 degrees Celsius (109.4 degrees Fahrenheit), creating challenges especially among the elderly during a day of prayer and reciting the Koran.

The hajj, which takes at least five days to complete and is mostly outdoors, "is not easy because it is very hot", said Abraman Hawa, 26, from Ghana.

"We have sun... but it is not as hot. But I will pray to Allah at Arafat, because I need his support," she added.

Saudi authorities have urged pilgrims to drink plenty of water and protect themselves from the sun. Since men are prohibited from wearing hats, many carry umbrellas.

More than 10,000 heat-related illnesses were recorded last year, 10 per cent of them heat stroke, a Saudi official told AFP this week.

The hajj, one of the world's biggest religious gatherings, is increasingly affected by climate change, according to a Saudi study that said regional temperatures were rising 0.4C each decade.