(Bloomberg) -- Hundreds of pilgrims died at the annual Hajj gathering in Saudi Arabia amid searing heat that the kingdom said was its biggest challenge this year.

Seven countries have separately announced a total of over 470 deaths during the five-day pilgrimage that ended June 18. The final number is likely to be higher as many nations haven’t yet reported their fatalities while unregistered pilgrims would also add to the toll. The AFP news agency said more than 1,000 have lost their lives as the temperature pushed 51.8C (125F) in Mecca this week.

While deaths at the annual pilgrimage aren’t uncommon due to a variety of reasons, the large numbers this year in the middle of summer are one of the starkest warnings of the risks from a warming world. Heat related deaths have been reported in India, parts of the US are in the middle of a heat wave and there are fears that rising temperatures may increasingly make some parts of the Middle East difficult to live.

Last week, Saudi authorities cautioned about “the significant rise in temperatures, which poses a threat to the health of pilgrims.” The health ministry later urged people to use umbrellas to prevent sunstroke. Over 2,700 cases of heat stroke were reported on Monday alone.

Hajj is one of the world’s biggest religious gatherings that this year drew over 1.8 million pilgrims from around the globe. It also generates large income for the country, bringing in around $12 billion annually for Saudi Arabia, according to estimates from Statista.

This come as Riyadh looks to position itself as the region’s primary financial center, rivaling Dubai. The kingdom’s Crown Prince Mohammed Bin Salman is pushing to open up the oil-dominated economy with investments in a range of sectors from tourism to artificial intelligence and infrastructure. The country has a target for net zero emissions by 2060.

Indonesia has reported 213 deaths at Hajj, India 98, Jordan 68, Tunisia 49, Malaysia 14 and Russia four. Egypt said it had 28 casualties. AFP put the number from the country at 658, including 630 unregistered people.      

The heat this year is also affecting other parts of the region. Egypt is struggling with severe energy shortages while some food production is being affected. Kuwait, a rich oil producer, this week resorted to power cuts as it was unable to meet demand amid soaring temperatures. 

The summer heat has taken its toll at Hajj before as well. Heat stroke caused 1,012 deaths during Hajj back in 1985 when the pilgrimage was in August and average temperatures reached 54C, according to a report from the Annals of Saudi Medicine.

Saudi officials have not made any official statements about deaths at this year’s Hajj. 

The dates for the pilgrimage come forward by about 11 days each year per the Islamic calendar’s lunar system. That will push the gathering closer to the cooler months over the next few years, and return to the peak of summer in the 2040s. 

Global warming — May this year was the 12th consecutive month of record-high temperatures — means the risks are only going to keep rising.

Listen on Zero: Cities Must Be Redesigned for a Future of Extreme Heat

--With assistance from Debjit Chakraborty, Yudith Ho, Anisah Shukry and Dana Khraiche.

©2024 Bloomberg L.P.