The 20,000-plus attendees who traveled to Las Vegas in July for EVO24, a global event where participants compete in virtual fighting games with names like Mortal Kombat and Street Fighter, arrived in the city during a historic heat wave, days after the temperature reached 120 degrees F.

The gaming news website Event­Hubs took time out from its coverage of upcoming virtual battles to warn about the very real danger that extreme heat could pose to those participating in the event, held July 19-21 at the Las Vegas Convention Center. In stories EventHubs reporter Dakota Hills posted on its website and shared on social media, participants were advised to avoid walking outside as much as possible and to plan their rides and routes to the convention center in advance. And although event organizers would provide more than enough free water for everyone inside the event venue, Hills wrote, “it would still be a very good idea to travel with extra water on hand and know where to get more if needed,” and for participants to familiarize themselves with the signs of dehydration and heat stroke.

The outside temperatures rose to 108 degrees F during the event, a few degrees lower than the forecasted 111 degrees F, and there were no publicly reported instances of participants suffering severe effects from the heat. But providing such warnings to event attendees, along with making other adjustments to events because of extreme heat, will become increasingly important as global temperatures continue to rise. In 2023, which was the planet’s hottest year on record, the number of deaths related to excessive heat were the highest recorded in 45 years, according to an analysis by Associated Press. This year could be even hotter — in the first six months of 2024, an “unprecedented” number of record-breaking temperatures were reported around the world, including “tens of thousands” of new local records reported from monitoring stations worldwide, climate historian Maximiliano Herrera told The Guardian in a story published Aug. 14.

Although extreme heat is the No. 1 weather-related cause of death in the U.S., killing more people most years than hurricanes, floods, and tornadoes combined, the threat is less well understood compared with more dramatic events such as storm surges and wildfires, according to a July 2023 story in Scientific American. “People tend to feel more uncertain about what to do under the threat of extreme heat and don’t perceive as much personal risk,” the article said. Heat-related risks are also more complicated to assess than the danger of rising water because multiple factors affect how outdoor temperatures will affect people, including humidity, wind, and the availability of shade, and individuals’ age and health conditions, which make some people more vulnerable to heat.

‘The Heat Happened Suddenly’

Cities in desert and other environments with a history of high temperatures have experience in adapting to the heat, as well as resources, including widespread air conditioning, which destinations in regions with more moderate temperatures often lack.

The heat wave that hit the forested Pacific Northwest from June 25 to July 2, 2021, “was something I’d never seen before in my lifetime,” said event sustainability expert Shawna McKinley, a principal at Clear Current Consulting in Vancouver, Canada. On June 29, temperatures rose to 121 degrees F in Lytton, British Columbia, setting an all-time heat record in Canada. There were hundreds of fatalities in the metropolitan Vancouver region, McKinley said, as well as in other parts of the Pacific Northwest, including Oregon and Washington. In British Columbia and elsewhere in the region, “people were not set up for air conditioning or prepared for [extreme heat],” McKinley told Convene. “The heat happened suddenly and it was made more likely by climate change.”

The unexpected heat’s devastating consequences in the region resulted in a number of changes designed to keep people safe, including public alert systems integrated with meteorological warnings about heat and delivered via mobile apps, McKinley said. “Residents get alerts when the temperatures go above a certain threshold for a minimum number of days and does not drop below a minimum temperature overnight, so that people can prepare.”

Those are the kinds of resources that destinations can be making event organizers aware of, and which can be used as part of a heat response protocol, McKinley said. The technology can help guide event organizers who are making decisions about bringing receptions indoors in the case of extreme temperatures or implementing things like cooling areas and hydrating refreshments to keep people safe in the shade at lower temperatures, she said.

Calculating Heat Risk

The U.S. National Weather Service and the Centers for Disease Control and Prevention have developed a new index designed to make it easier for decision makers to calculate the risk that heat poses to the general population. The NWS HeatRisk index, which is searchable by ZIP code, combines multiple factors that contribute to heat stress to gauge the risk of heat-related health impacts, and provides heat-protection recommendations.

Barbara Palmer is deputy editor of Convene.

More From Convene

“How Extreme Weather Impacts Events” covers event sustainability expert Shawna McKinley’s research report on the impact of extreme weather on events in Canada in 2023.
Rhanee Palma, CDME, operations and events manager for the UC Davis Air Quality Research Center, shares four ways to protect your attendees from extreme heat.