The International Triathlon Union’s (ITU) decision to reduce the distance of the run segment in yesterday’s women’s Olympics qualifying event because of heat concerns was the latest setback for next year’s Tokyo Games organizers battling extreme temperatures.

The union reduced the distance of the run section due to concerns that the weather conditions at the end of the race would have fallen within “extreme levels.”

It is the latest of the Tokyo Games’ test events to highlight concerns over the sweltering summer temperatures that can be expected at the Olympics from July 24 to Aug. 9 next year.

Soaring temperatures have killed at least 57 people across Japan since late last month, highlighting the possible health threat to athletes and fans.

Lessons would be learned from the triathlon event, Tokyo Games spokesman Masa Takaya said.

“The ITU informed Tokyo 2020 that a comprehensive review is necessary soon after the competitions this week,” Takaya said in a statement. “In this respect, we will continue to work closely together with the team.”

“Tokyo 2020’s collaboration with the ITU [has] led to the implementation of measures to combat summer heat, including [a] change of races’ start time, revised heat stress protocols, specially trained personnel and extra water stations on the course,” he added.

The swimming and cycling segments remained the same after the ITU deemed that the water quality and temperature at Odaiba Marine Park were within regulation.

However, yesterday’s triathlon race was another setback for organizers, following a difficult period of test events.

Kyodo News last weekend reported that several athletes were treated for heatstroke at the World Rowing Junior Championships in Tokyo, which was another test event.

There were also complaints from spectators at the lack of protection from the sun, as the venue was constructed with the roof only covering about half of the 2,000 seats.

The decision was made in 2016 to reduce the size of the roof at the then-new venue as a cost-cutting measure by the Tokyo Metropolitan Government.

“We will not be changing the venue in any way and will not be increasing the size of the stand cover before the Tokyo 2020 Olympics,” the city government told reporters via e-mail.

At the swimming marathon test event last weekend, also held at Odaiba Marine Park, local media reported athletes complaining of a bad smell in the water.

However, Tokyo organizers earlier this week said that the water quality was not an issue for the union, which was prepared to let its test event go ahead as scheduled.

“The test results for the past week show that the water quality is good enough and that the number of E. Coli and enterococci are continuously well below the level of ITU criteria,” organizers said in a statement on Tuesday.

They added that they would install more filtering screens ahead of the Games to those already in place after 2017 tests showed levels of Escherichia coli up to 20 times above the accepted limit and fecal coliform bacteria seven times higher.

Single-layer screens installed in Tokyo Bay have helped reduce the bacteria, organizers said.

“For next year, we will install triple-layer screens to assure the successful delivery of the competitions,” they said. “The installation of triple-layer screens takes a significant amount of time … [so] we decided to go with the single-layer screen under the agreement with the federations.”