Bob Hersh, an American who is also an IAAF vice president, said the weather would be something council members must “reflect upon” when choosing either Doha or London to host track and field’s showpiece event.

Hersh spoke after his evaluation panel finished a two-day visit to the desert nation, just over a month before the International Association of Athletics Federations chooses the host city in Monaco on Nov. 11.

Hersh said he was impressed with Doha’s plans to air condition the main stadium and hold the marathons at night when temperatures are cooler. He said air conditioning “needs to be done” to “create a more favorable environment for athletes and spectators.”

Qatar, which is also bidding for the 2020 Olympics and won the right to host the 2022 World Cup, proposes holding the competition from Sept. 9-17. London plans to hold the event in late July or early August.

“It’s hot,” Hersh said. “We all know that the heat is an obvious concern here in Doha in the month of September when championship is proposed to be held. What the Qataris showed us is the possibly of air conditioning an open stadium.

“We were out there this morning and saw actual demonstration of that …It’s developing the technology but you could see the potential and that air conditioning an outdoor stadium can be done.”

The Qataris said a solar-powered cooling system is planned for the 40,000-seat Al Khalifa Stadium. The system will blow cool air below the seats and cool the field, part of a $400 million renovation of the 35-year-old facility that will be finished a year ahead of the competition, organizers said.

While summer temperatures in Qatar and the region as a whole can soar above 104 degrees, Hersh said tough conditions are nothing new for world championships.

He ticked off several examples including the 1997 competition in Athens, Greece, and 1999 in Seville, Spain, where the weather was extremely hot.

“We have had athletes competing in warm weather and it is something that athletes deal with,” Hersh said. “It is certainly not a deal breaker. The fact we have world championships in warm weather in the summer months almost inevitably means in certain places it will be warm.”

Inspectors came to Qatar after touring facilities in London, where bid organizers played up what they contend is their clear advantage when it comes to weather.

The London bid team argued that the conditions would be more welcoming to athletes and that athletes were more likely to break records since they would be competing in natural conditions and at a time they normally compete in a world championships—rather than a month later.

But Qataris have become accustomed to criticism of the heat—they were inundated with complaints ahead of their successful bid to host the 2022 World Cup. They refused Thursday to get into public spat with London over the weather, choosing instead to focus on what they said are the merits of their bid.

They showed inspectors a new convention center where they propose the IAAF convention would be held as well as a massive athletes’ village that is under construction and would be able to house 3,500 competitors. The village will feature apartments, two five-star hotels and restaurants.

“We are confident, very confident with our bid file,” said Sheik Saoud bin Abdulrahman Al Thani, the secretary general of the Qatar Olympic Committee. “We are not only confident in our bid file but confident that we can take the world championship to the next level. We are promising to do one of the best world championships and that we can remove any barriers in terms of heat.”

Al Thani said bringing the world championships to the Middle East for the first time would allow the IAAF to expand its reach and tap a market of at least 450 million people. He said it would also open the door for other arid nations to host big sports events.