Tour de France Faces Growing Heat Stress Risks as Temperatures Rise

The Tour de France, one of the world’s most iconic and grueling cycling races, is facing an escalating threat from rising temperatures and increasing heat stress risks for its competitors. Recent research indicates that the current format and timing of the race are becoming increasingly questionable due to the potential for dangerous conditions for cyclists, teams, and even spectators.

Rising Heat Stress Levels

A study published in Carbon Brief, utilizing 50 years of climate data, reveals a significant increase in both the severity and frequency of high-heat-stress events across France in recent decades. The research, also highlighted by Phys.org and Scienmag, analyzed conditions across a dozen locations frequently visited during the race.

Researchers employed the Wet Bulb Globe Temperature (WBGT) – a comprehensive heat index that considers air temperature, humidity, solar radiation, and wind speed – to assess the risk. While the heat-stress threshold for safe competition, as set by cycling’s international governing body in 2024, has rarely been breached thus far, the study warns that it is “only a question of time” before it is exceeded given the continued rise in average temperatures.

A Race Against Time

Dr. Ivana Cvijanovic, a climate scientist at the French National Research Institute for Sustainable Development (IRD) and lead author of the study, explained to Carbon Brief that race organizers have been fortunate to avoid major heat stress incidents to date. Though, she cautioned that “it will be harder and harder to be lucky” as extreme heat events grow more commonplace. The research was a collaborative effort involving the London School of Hygiene & Tropical Medicine (LSHTM) and the Barcelona Institute for Global Health (ISGlobal).

The Tour de France, covering approximately 3,500 kilometers (km) and nearly 55km of altitude gain over 21 stages, presents a unique challenge to athletes. The race demands immense physical exertion over an extended period with limited rest days.

Impacts and Potential Changes

The increasing heat poses a direct threat to rider safety. In 2022, Alexis Vuillermoz, a French competitor, collapsed at the finish line of the Tour’s ninth stage and was forced to withdraw from the race.

Climate experts, as reported by The National News, are calling for major changes to the Tour de France to mitigate these risks. They suggest the current format and schedule are “becoming questionable.” Recommendations include following the lead of other sports federations, such as FIFA, which have implemented hydration breaks to protect athletes.

Teams are already proactively addressing the issue by conducting physiological data analysis on riders and employing heat acclimatization training. Riders also utilize cooling strategies during races, such as consuming ice gels.

Looking Ahead

The challenges faced by the Tour de France are indicative of a broader trend impacting summer sporting events in Europe, and beyond. The need for sport-specific research and “bold decisions” is becoming increasingly urgent as temperatures continue to climb. The 2026 Tour de France, scheduled from July 4 to 26, will be closely watched as a potential test case for adapting to the realities of a warming climate.