Tokyo 2020 organisers blasted volunteers with fake snow on Friday as they try ever more extreme ways to beat the heat ahead of the Games.

But instead of light fluffy snowflakes, the crowd, consisting mainly of Tokyo 2020 staff, was pelted with fairly coarse shards of shaved ice at the canoeing test event.

And ironically, after several weeks of almost unbroken heat and humidity, Friday saw temperatures in the Japanese capital drop sharply – no doubt a relief to millions of Tokyo commuters and players training for the forthcoming Rugby World Cup.

“We are trying everything possible to ease heat risks,” said Taka Okamura, from the 2020 organising committee.

“This is not meant to cool the entire atmosphere but have spectators feel refreshed when the flakes of ice touch them,” added Okamura, who acknowledged that the system needed some refinement.

One problem became immediately apparent after the volunteers were doused in 300 kilograms (650 pounds) of snow in a matter of minutes: the “spectators” were quickly soaked through and the floor became slippery – resulting in one journalist taking a tumble.

Okamura played down any environmental risks from the system – such as CO2 emissions from the machine – and declined to reveal its cost. Tokyo 2020 officials have admitted in the past that anti-heat measures will swell the budget for the Games.

Tokyo 2020 organisers have largely won praise for their preparations for the Games. With the construction work on track, IOC President Thomas Bach has said Tokyo is the best-prepared host ever with less than a year to go until the opening ceremony.

But the sweltering Tokyo heat has already proved a headache and there are fears for athletes, volunteers and spectators if conditions in recent summers are repeated at Games time.

Test events in August did little to allay those fears, with a French triathlete taken to hospital with suspected heatstroke, complaints about the water temperature for marathon swimming, and people taken ill at a rowing trial.

One member of the French para athletics team attending Friday’s event pointed to another potential problem of the fake snow hose.

“When the wind is blowing in the wrong direction pushing the snow out of the stands, I’m not sure it is going to be that efficient,” he said.

Top doctor sounds alarm over heatstroke at Tokyo 2020

One of Japan’s top doctors has slammed the decision to hold the Olympics at the height of Tokyo’s baking summer, warning that heatstroke will be the “biggest risk” during the Games.

In an interview with AFP, Kimiyuki Nagashima, executive board member of the Japan Medical Association, also sounded the alarm that the Olympics will stretch the country’s doctors at a time when local families are most at risk from the heat.

And it’s not just the heat: Nagashima cautioned against the risk of communicable diseases as people fly in from around the world and gather en masse. Measles is thought to be a particular risk as many Japanese are not adequately vaccinated as children.

“My personal opinion as an individual is that sporting events should be held in a comfortable environment. I don’t think it is agreeable to hold it at an inappropriate period at an inappropriate location due to business and economic concerns,” he said.

The sweaty Tokyo summer is “generally speaking not a suitable place” for outdoor sports and for their spectators, added the doctor, an orthopedic surgeon who oversees the association’s sports medicine activities.

In the city’s bidding document to win the Games, Tokyo said the competition period between July 24 and August 9, followed by Paralympic Games, “provides an ideal climate for athletes to perform at their best” with “many days of mild and sunny weather.”

However, last summer, nearly 93,000 people sought emergency care across Japan, with 159 of them dying. Most of these cases took place during the time the summer Olympics will take place.

“From the start, we have seen heatstroke as the biggest risk factor for the Tokyo 2020 Olympics as far as health goes,” Nagashima said.

Humidity ‘extremely high’

The 1964 Tokyo Olympics were held in October to avoid the heat of the summer and the issue has quickly become the major headache for organisers.

They have brought forward the start time for several events including the marathon and rolled out a variety of anti-heat measures.

However, recent test events did little to cool fears, with a French triathlete treated for heatstroke and several spectators taken ill at a rowing trial.

Many test events took place under conditions regarded as “dangerous” for exercise, according to the internationally accepted WBGT index that measures heat and humidity.

Nagashima said he had urged organisers to think beyond the Games and be “fully considerate” that medical emergencies during the competition will divert resources away from locals at a critical time.

“Japan’s heat is not just about the high temperature. Humidity is extremely high... This means a higher risk of getting sick than in other countries,” he said.

But given that Japan is determined to host the event, the nation must prepare itself and offer visitors advice to stay healthy, the doctor said.

“There are steps you can take to avoid heatstroke. Please learn about heatstroke. Take preventative measures. Then please come to Japan and enjoy the Olympics in comfort,” he said.