Too hot to handle? Heat’s impact on our health and (Olympic) performance

Issue 85 l Eka’s Weekly Roundup (13 August 2024)

Aug 13, 2024

The world is getting warmer.

Heat deaths increased +70% globally between 1990 and 2016. Extreme heat instances are expected to grow even under a 1C warming scenario.

This matters, because the health impacts on prolonged heat exposure range from heatstroke to chronic disease. There have been very few papers on the heat’s unequal impact on 1) ethnic groups and 2) income groups but a UK government paper suggests that these heat health inequities are likely to mirror broader health inequities.

“Heat health” has been top of mind since the Paris Olympics. Some athletes suggested that the heat had a tangible and measurable impact on performance. For comparison, the 2024 Paris Olympics were 1C warmer than the 1924 Paris Olympics, and Tokyo 2020 was 3.5C warmer than the 1900 Olympics.

Read on if you’re curious about how heat & humidity levels are changing, and understanding their impacts on human health and athletic performance.

As ever, if you’re building in the adaptation space, let us know at estia@ekavc.com or our submissions portal.

Heat, health, and performance 🗞️

A closer look at rising temperatures - when is too hot really too hot? At about 35C and 75% humidity.

The world is heating up. Climate data reveals a steady increase in global temperatures, with new records being set almost every year.

Impacts on global humidity have been more mixed. Specific humidity (water vapour) has increased in much of the world. However relative humidity has declined. Air can generally hold around 7% more moisture for every 1C of temperature rise, which explains the rise in specific humidity.

We’ve been particularly interested in both of these trends after learning about the learning about Lethal Heat. This paper from 2023 showed how a theoretical impact of 35C and 75% humidity would impact global health. Theoretically, humans would only be able to survive 6 hours at this exposure given this level of heat causes perspiration which struggles to dry at high humidity levels.

These 6-hour heat instances have increased from c600 instances per year between 1980-2000, to c1.1k instances per year in since 2015. This is unevenly distributed globally, occurring mainly at the Equator.

Then, we can see what the heat instances could look like based on different warming scenarios from 1C to 3.5C based on return periods. These are an average time or an estimated average time between these heat events. In other words, many regions would have these heat moments about once a year under the extreme scenarios.

Example 1: Heat health inequalities are likely to be similar to broader health inequalities

While the rising temperatures are a global issue, their effects are felt unevenly across different communities.

The push for energy-efficient housing with high insulation, designed to keep us warm in the winter, can turn our homes into heat traps during increasingly hot summers. Those without access to air conditioning, often in lower-income areas, are particularly vulnerable to heat-related health problems.

On the other hand, wealthier individuals can afford to install and run air conditioning units, creating a stark divide in how different socioeconomic groups experience and cope with the heat.

The UK Government published a paper about Heat’s Health Impacts in May 2024 and called for more evidence to be gathered around the inequalities of heat impacts, but noted that minorities typically face large health inequalities in other domains.

Example 2: Heat at the Olympics and impacts on performance

Grist wrote an interesting piece this week on the impact of heat at the Paris Olympics: How the 2024 Paris Olympics handled the heat — and didn’t.

Temperature can also be timestamped by the Olympics. For example, the Tokyo Olympics were 2.5C warmer than the 1900 Games. The Paris Games in 1924 were 1C cooler than the ones this year.

This is a colourful example, from the Grist article:

Curled up on a small, white rectangle of fabric on the grass by a park bench in Paris, Italian swimmer Thomas Ceccon inadvertently took the internet by storm simply by sleeping outside. The moment, posted to social media on Monday by a fellow Olympic athlete, came a week after Ceccon failed to qualify for the men’s 200-meter backstroke finals, despite having just won gold in the 100-meter event.
In an interview with an Italian broadcaster, Ceccon blamed his performance gap on subpar sleeping conditions in the Olympic Village — namely, heat. This week, media speculation that the uncomfortable temperatures were also behind his alfresco nap stirred an already roiling pot of concerns around the impact of extreme weather on this year’s summer games. (The Italian Swimming Federation denied that Ceccon’s nap was related to conditions in the Olympic village.)

Elite athletes are not immune to the effects of rising temperatures, and future games will increasingly need to consider heat adaptation.

Adapting to heat is a necessity, not a choice

The trend of rising temperatures shows no signs of slowing, making it crucial for us to think about how we can adapt. This isn’t just about finding ways to stay cool in the short term; it’s about developing long-term strategies to cope with a hotter world.

For example, bodies of water & forests are good ways to reduce the temperature during heatwaves. See Paris below during a June 2022 heatwave.

Urban planning, public policy, and corporate innovations will need to evolve to ensure that communities are prepared to handle extreme heat.

From more green spaces that provide shade to ensuring equitable access to cooling resources, adaptation will be key to protecting our health and well-being in the years to come.