Extreme heat threatens future Summer Olympics

Athletes are raising concerns about scorching temperatures at the 2024 Paris Olympics, which could affect not only athletes and attendees' health but also athletic performance.

Why it matters: It's only going to get worse. Climate change promises hotter summers, meaning suitable venues for the Summer Games will become only more scarce.

• Since the last Summer Olympics in Paris, in 1924, July and August temperatures have increased by 2.4°C and 2.7°C, according to the British Association for Sustainable Sport and Frontrunners.
• A 0.5°C increase can raise heart rates about 10 beats per minute, which elevates the risk of heat illness.
• And it's not just the Olympics - tennis grand slams, the FIFA World Cup and countless other global sporting events traditionally held in summer months are put at risk.

Struggles Facing Paris

In Paris, heat waves pose great risk. Last summer, France was hit by four heat waves, causing more than 5,000 deaths.

Background: Trees, parks and other green spaces help to moderate heat, while dense buildings tend to trap and intensify heat.

• Paris is particularly vulnerable, with a high density of buildings and low green space compared to many other large European cities.

Green spaces regulate temperatures

Average vegetation and surface temperatures in Paris, June to September 2023

Green space

Surface temperature

Data: Landsat 8

Not a new problem

Flashback: Heat has always been an issue at the Summer olympics.

• The first recorded death was in 1912, when marathoner Francisco Lázaro died from dehydration in Stockholm.
• Nearly 50 years later at the 1960 Rome Olympics, cyclist Knud Jensen suffered a heat stroke and later died of related head trauma.

Threat level: According to Zachary Schlader, an associate professor who studies heat stress at Indiana University Bloomington, events with a long duration and no breaks such as cycling or distance running pose the greatest risk for heat illness.

• During the Tokyo 2020 Olympics, nearly three-quarters of heat illness cases occurred during endurance competitions.
• But Schlader said he's more concerned about spectators and staff: "An athlete is super healthy, right? But now, you take the general public, throw them in a stadium, close together, and put oppressive heat on them. Those people that have underlying health conditions are at greater risk, and they can't always regulate the same as someone that's young and healthy."

It's only getting hotter

Projections from CarbonPlan, a nonprofit that researches climate solutions, show that by 2050 a majority of the world will be too hot in the late summer to host the Olympics.

By the numbers: By 2050, models show, during the period of the Paris Olympics 60% of locations will experience Wet Bulb Globe Temperatures above a "cancel activity" level, compared to 50% of locations experiencing that level today.

• One way to avoid such dangerous heat is to hold the Olympics in the spring or fall, as was done for the 1964 Tokyo Olympics or the 2022 FIFA World Cup in Qatar.
• During the 2020 Tokyo Olympics, endurance events were rescheduled to the morning to avoid the hottest times of day, but even so, 60% of heat-related illness occurred during these morning events.
• If the Summer Olympics continue to be held in July and August, suitable locations will be narrowed to cities in Canada, northern Europe and Russia, or to the southern hemisphere, where July and August fall in winter.

Wet Bulb Globe Temperatures during the Olympics

2020

2050

Data: CarbonPlan

In 2028, the Olympics will return to Southern California, where the IOC is already planning to implement heat protocols.

• "Los Angeles is a big issue," said Sebestian Racinais, who chairs the IOC's group on extreme environmental conditions. Racinais is optimistic, noting that the U.S. already has protocols in place for heat illnesses, and pointing to the research done by the U.S. Army and NGOs like the Korrey Springer Institute, which is dedicated to research in exertional heat stroke in sports.
• "In American football, you get some casualty every year, unfortunately, related to exhaustion or heatstroke, so that also means you have some stimuli to that," Racinais said. "It will be quite easy in the U.S. to find a physician, athletic trainer and people trained on that issue."

What's next?

In a warming world, host cities and sports federations are turning to technology and expanded safety protocols. The Paris 2024 committee has created infrastructure to reduce the pressure of heat.

• There's special permission to allow water bottles and refillable stations throughout the residential area, with about one fountain for every 300 spectators.
• 9,000 trees were planted around the athletes' village to protect against sunlight, and covered paths will feature protective screens to shield spectators from the sun.
• Such measures help but don't necessarily solve the problem: at the Tokyo Olympics, the IOC implemented heat decks, facilities for treating heat illness. But nearly 1 in every 100 athletes experienced illness, with athletes vomiting and fainting at the finish line.

Separately, other sports federations have prepared for rising temperatures, particularly in France.

• Roland Garros, where the French Open is held, added a retractable roof prior to the 2024 French Open. Although the roof primarily serves against inclement weather, such roofs have been deployed in other locations to provide shade during extreme heat.
• During the 2019 Women's World Cup in France, FIFA relaxed its drink ban, allowing fans to bring in water bottles to stadiums, and implementing cooling breaks during matches.

Of note: While the IOC makes recommendations for heat protocols, the Paris 2024 committee coordinates with each sport's governing body to make sure the competitions take place in appropriate conditions.

Paris is experimenting with using water from the Seine River to cool buildings. Their passive cooling system pumps water into the Olympic Village apartments to keep them between 73°F and 79°F.

• But many countries doubt the system will be sufficient and plan to bring portable air conditioners.

The city hopes to expand its passive cooling system to other critical infrastructure, such as day cares, hospitals and retirement homes.

What to watch: The IOC have not ruled out any future locations, with bids coming from hotter climates such as Riyadh, Saudi Arabia, and Doha, Qatar, for the 2036 games.

• Both have been selected for other global events, such as the FIFA Men's World Cup.

A team led by Racinais has sent recommendations to the IOC and made mandates at events to reduce heat stress, such as hydration stations for spectators and procedures for warm-up and cool downs for athletes.

• The IOC president, in a statement to the Indian Express, suggested moving the Olympics to cooler months, or even focusing on indoor sports.