The June heat wave which hit the runners of the Tour de Suisse and the Route d'Occitanie hard is part of an underlying trend.

Between the three editions of the Tour de France from 1999 to 2001 and the last three which took place in July (2018, 2019 and 2021), the average temperature recorded on the roads rose from around 29.6 degrees to 40.1 degrees .

The "Mister Route" of the Tour, André Bancalà, coordinator of the Departments of France, shared with AFP his data recorded and compiled since 1999. He records, using a gun, the air temperatures and from the ground, at kilometer zero, mid-stage and just before the finish (at the red flag) to ensure that the roads do not "sweat" under the effect of the heat, i.e. they do not soften and become slippery.

André Bancalà kept his readings and calculated averages for each edition of the Tour de France, only taking into account the week preceding July 14 and the following one to clip the departures abroad from his data and neutralize, as much as possible, the changes. dates of the Tour de France, because of the Olympic Games for example.

"The increase in ground temperature is more noticeable because I imagine that the additional half degree or degree has more impact on dark road surfaces", describes André Bancalà.

This stored heat is then transmitted to the runners.

Protocol "extreme temperatures"

"I have not measured the temperature of the roads but we can see that the environment is changing a lot", confirms the performance director of the Jumbo team Mathieu Heijboer.

"Normally we only use refresh strategies a few days during the Tour, a little more during the Vuelta but it's more and more often".

Dutchman Fabio Jakobsen (c) wins the 2nd stage of the Tour de France in the sprint on July 2, 2022 in Nyborg (Denmark) Anne-Christine POUJOULAT AFP

“We use cold-weather clothing outside the race and cold collars in the race,” explains AG2R Citroën team doctor Thomas Klimaschka.

"Runners must be reminded to drink enough and monitor the potassium threshold, lost with perspiration. They can absorb it in tablets or with a drink in a canister."

Seven Tour de France teams also use a sensor to measure body temperature during the race, according to manufacturer Core sensor.

"It's a possibility but at the moment (with an air temperature) between 30 and 35 degrees, we are used to reacting", describes Dr Thomas Klimaschka.

Beyond that, in the event of "extreme temperatures", the protocol of the International Cycling Union provides for the possibility of a "change of route or neutralization of part" of it or even "cancellation of the stage or the race".

Ice maker and refrigerated gels

Even when it does not endanger the runners, to the point of suffering from heatstroke, high temperatures are a parameter monitored by the teams.

The new Jumbo team truck since last year includes an ice maker.

“We also use cold nutrient gels at temperatures of 0 to 2 degrees to cool the body from the inside,” explains Mathieu Heijboer.

In addition to aerodynamics, their textile supplier "develops clothing that ventilates more".

Belgian Yves Lampaert, first yellow jersey of the Tour, during the 2nd stage between Roskilde and Nyborg (Denmark), July 2, 2022 Etienne GARNIER POOL / AFP

The temperature record recorded by André Bancalà is 63 degrees on the ground in the resort of Les Rousses in 2010 during the stage won by Sylvain Chavanel.

© 2022 AFP