The beginning of the end for the Tour de France? Scientists warn it's 'only a matter of time' before France becomes too HOT to host the famous cycling race

The Tour de France is the oldest and most prestigious cycling race in the world, covering roughly 2,100 miles (3,500km) across France and its neighboring countries.

However, we might soon need to rename it, with the race forced to move countries entirely. 

That's according to scientists from the Barcelona Institute for Global Health, who say it's 'only a matter of time' before France become too hot to host the annual event. 

In a new study, the team analysed climate data at various host locations between 1974 and 2023. 

Their results show that the risk of heat stress has increased over the years – and may soon be too high for athletes.

'In our analysis, we observe that the city of Paris, for example, has crossed the high–risk threshold for heat on five occasions in July, four of them since 2014,' explained Ivana Cvijanovic, first author of the study.

'Other cities have experienced many days of extreme heat in July, but thankfully not on the date of a Tour de France stage.

'In a way, we can say that it is an extremely fortunate race, but with record–breaking heatwaves becoming more frequent, it is only a matter of time before the Tour encounters extreme heat stress day that will test existing safety protocols.'

Dating back to 1903, the Tour de France is the oldest cycling race in the world. 

It takes places in July and the route changes, although the format tends to stay the same – with a large chunk through the Pyrenees and the Alps, and a finish in Paris. 

In their new study, the team set out to understand how the conditions have changed at the event over the years. 

The researchers used a heat index known as the Wet Bulb Globe Temperature (WBGT), which combines several variables to estimate heat–related health risk. 

This includes air temperature, relative humidity, solar radiation and wind.

The team analysed historical meteorological records for 12 locations frequently visited by the Tour de France, as well as for all July dates corresponding to the different editions of the race. 

Using these data, they calculated the WBGT values and analysed the occasions on which the high–risk category was reached.

Their results showed that episodes of dangerous heat levels have been most common around Toulouse, Pau and Bordeaux in southwestern France, and around Nîmes and Perpignan in the southeast. 

Meanwhile, Paris and Lyon are increasingly crossing the high–risk heat threshold, becoming 'new heat stress hotspots'. 

'Extra caution should be exercised when planning stages in these regions,' said Desislava Petrova, one of the researchers. 

In contrast, classic mountain stage locations such as the Col du Tourmalet and Alpe d'Huez have remained within low to moderate heat stress risk thresholds, with no recorded episodes of extreme heat risk to date.

The researchers also looked at heat stress risk at different times of the day. 

This revealed that morning hours remain the safest part of the day, while late in the afternoon is the most dangerous time for cyclists.  

Based on the findings, the researchers say that schedules, routes, and safety protocols should be reconsidered for future Tour de France events. 

'Science still has many unanswered questions about how the human body responds to heat, and even more so in the case of elite athletes, who face sustained physical exertion while also having physical conditioning and training levels well above those of the general population,' said James Begg, one of the study researchers. 

'To investigate sport–specific vulnerabilities, we would need access to anonymised physiological data that would allow us to go beyond heat indices alone.'