Heatstroke, Backstroke, and the Summer Olympics

Tokyo Drifted into a Sauna

Katie Pflaumer, Marketing Communications Manager for the American Meteorological Society, wrote this week’s newsletter.

What might Summer Olympics venues have in common in 15 years?

A study presented at last January’s AMS Annual Meeting in New Orleans suggests they may have a certain geographic south-iness, or possibly an altitudinosity.

Temperatures and heatwaves are increasing worldwide as climate change intensifies, making some places harder to live in. Increasing heat, plus humidity, plus all the running and jumping and spinning around that Olympians do (they also participate in Olympic contests) could spell disaster.

“This is actually just how I commute.” (Photo by cottonbro studio on Pexels)

Heat stress has already caused problems at previous Summer Games. In Tokyo 2020, organizers had to move events to (slightly) cooler regions and reschedule events for the evening. Tennis player Novak Djokovic said they were the worst conditions he had experienced in his 20-year career.

In their study, Milena Raeber and colleagues examined heat risk to athletes across all 880 global cities large enough to host the Olympic Games (600k+ population). They looked at changes in the risk of human heat stress in each city during June–October, the time window in which the Summer Games are held, using historical data from 1983–2016 to model projections for 2050.

Classing It Up

The Olympics can be divided into sports and events. A given sport can have few events (Golf, for example, has two: men’s and women’s) or many (“Athletics” has 47 events, from shotput to marathon). These sports can have very different sensitivities to heat stress due to exertion, clothing, location, etc.

The researchers grouped the Olympic events into five different classes of risk based on exercise intensity and clothing/equipment worn. The categories were established by Sports Medicine Australia, then adapted to better represent the Olympics’ many offerings. Class 5 sports (like mountain biking) have the highest risk for heat stress. Events like the shotput were categorized as “Athletics” and placed in Class 1, lowest risk.

The five sports heat risk categories used in this research. (Image courtesy of Milena Raeber, from her AMS 105^th Annual Meeting presentation, “Heat Stress Risk for Summer Olympics in a Warming Climate.” Adapted from Sports Medicine Australia [SMA])

An example heat risk plot from Raeber’s presentation, for sports in Category 1, showing extreme heat conditions based on air temperature and relative humidity. (Image courtesy of Milena Raeber, from her AMS 105^th Annual Meeting presentation, “Heat Stress Risk for Summer Olympics in a Warming Climate.” Adapted from Sports Medicine Australia [SMA].)

SMA issues guidelines for all five categories. As an example, a temperature of 35°C (95°F) and relative humidity of 60% would count as “extreme risk” under which a mountain bike race shouldn’t be held. I would also prefer not to exercise under those conditions, yet another way I am basically an Olympian.

Raeber and colleagues calculated the percentage of time conditions are considered “extreme” risk for each sports category in each city during June–October. They also factored in the number of sports events held in those categories to create a summary metric (“probability of event suspension”) for each city. This represents the probability of any given Olympic event in that city being suspended due to the risk of heat stress.

The Summary Metric includes data from meteorological computer models, historical records, the heat risk of the sport, and how many events are held within the sport. (Image courtesy of Milena Raeber, from her AMS 105^th Annual Meeting presentation, “Heat Stress Risk for Summer Olympics in a Warming Climate.”)

Off the Map?

The Tokyo Olympics had the greatest probability of event suspension in recent decades, 15%. Indeed, it was considered one of the warmest and most humid Olympiads ever. Assuming the threshold for kicking a city out of Olympic contention should be a bit higher than that, Raeber and co. calculated that 579 of our 880 Olympic-sized cities have historically had a 25% or lower probability of event suspension. By 2050, however, more than a quarter of those cities (149) will no longer meet that threshold and appear likely to fall off the Summer Olympics map if they can’t figure out how to mitigate increased heat stress risks.

Projected probability of Olympic event cancellations in different global cities due to heat stress, based on model projections for the year 2050. Red represents the highest likelihood of at least one event being suspended, and dark blue represents the smallest likelihood. The authors assumed a 25% probability of event suspension as the upper limit for an Olympic host city. (Image courtesy of Milena Raeber, from her AMS 105^th Annual Meeting presentation, “Heat Stress Risk for Summer Olympics in a Warming Climate.”)

The remaining 430 cities were more likely to be high-elevation, farther from the equator, or in the Southern Hemisphere. Yes, some of the best places to hold the “Summer” Olympic Games in the future will be places where it is, technically, winter.

Olympic baseball is back! (Image by Victoria on Pixabay)

On average, the probability of event suspension is due to increase by 36% in the next 15 years due to a warming climate.

Of course, humans are ingenious creatures, and we have innovative health interventions as well as things like buildings and air conditioning—though those come with their own costs in terms of energy and construction. We can’t know what the IOC will decide about how and where (and if?) to host the Olympics in the future.

Will we move everything indoors? Switch the timing of the Summer and Winter Olympics? Hold events at the top of a mountain? Build a giant sun blocker?

Warning: Be very careful when doing the shot put. (Photo by Jonathan Lewis, on Wikimedia Commons)

Combine the Summer and Winter Olympics and do them all in the southern hemisphere at the same time?

“I am here for the ice dancing.” (Photo: MojNews, on Wikimedia Commons)

Time will tell.

And Now for Something Completely Different

Dr. Barb Boustead is a longtime NOAA climatologist, meteorologist, and educator. She is a massive fan of the author Laura Ingalls Wilder, having even served as the former president of the Laura Ingalls Wilder Legacy and Research Association (LIWLRA).

Dr. Boustead recently published her magnum opus 7 years in the making, a book about the impact of weather in the Little House on the Prairie book series and, contrariwise, the impact the series has had on our understanding of weather!

Our cat Maggie promoting the book. This isn’t animal servitude; she was paid in treats.

You can pick it up at your local bookstore, order it on Amazon, or purchase it directly from the publisher.

Here's an interview Dr. Boustead did with Wisconsin Public Radio discussing the book. She also writes a Substack newsletter of the same name, which covers some of the topics in the book, as well as her perspective on a wide variety of other meteorological and climate-related topics.

We are grateful to Lockheed Martin for a grant to support this newsletter.

Our archive of WWAT articles is here.