At the 1978 24 Hours of Le Mans, Didier Pironi took the last two stints, at the hottest time of the day. The roof of the #2 Renault Alpine A442 B was made of Plexiglas, which made life in the cockpit practically unbearable. He won the race but fainted during the administrative procedure at the finish. Luckily, the race doctor was present at the scene, unzipped the driver’s firesuit and covered him in ice.

Jacky Ickx, who had been chasing the Alpine in the Porsche 936, finished five laps behind. He didn’t faint but was considerably weakened, having spent 14 hours at the wheel and lost 6kg in the process.

In 1991, the finish line scenario was similar. Johnny Herbert claimed the trophy in the #55 Mazda 787 B that he shared with Volker Weidler and Bertrand Gachot.  He was two laps ahead of the Jaguar XJR 12 (Davy Jones/Raul Boesel/Michel Ferté). But Herbert didn’t have time to savour his victory. He fainted from dehydration as soon as he saw the chequered flag and headed for the medical centre rather than the podium! Like many drivers, he had avoided eating too much during the race due to a delicate stomach. The Briton is therefore the only Le Mans winner not to have lifted the trophy after the race! However, in 2011, for the 20th anniversary of the only victory for a Japanese car at Le Mans, Herbert did a lap of the circuit in the Mazda and was able to enjoy a special podium ceremony organised just for him.

When temperatures rose during the race, pit crews cooled drivers by emptying buckets of ice over them during pit stops. Not the most high-tech of solutions!

In 2005, temperatures reached 80°C in closed-cockpit cars. Stéphane Sarrazin, who will be driving the #7 Toyota in LMP1 this year, has painful memories of that year. “I was driving the front-engined Aston Martin DBR9. I thought I was literally going to melt. It was beyond belief. You can’t imagine what it was like, you have to have experienced it. When I finished my stint, my team carried me to the air-conditioned truck and put me in a tub of cold water. But half an hour later, they came back to say I had to get back in the car. Darren Turner had just fainted as he was about to get in the car and David Brabham couldn’t stand in for him because he had burns on his feet from the pedals. I finished the race in dire conditions and I’ll never forget it. It’s the absolute worst moment of my career.”

Sarrazin’s Aston Martin finished ninth that year. Romain Dumas, in the #36 Alpine A470 this year, had a similar experience. “In 2005, I was with Sébastien Dumez in a Porsche. It was so hot in the cockpit - over 60°C - that he fell ill in the first hour. When we got out of the car, we put our feet in a bucket of ice.”

The ACO was quick to react and the 24 Hours of Le Mans was the first race to make air-conditioning a requirement, as of 2007. Car weight was increased by 25kg to account for the new regulations.

Current rules also require air conditioning in LMGTE and LMP2. In article 16.8 of the LMP1 regulations, prototypes must be equipped with efficient natural aeration and/or air-conditioning. Prototypes and GTs are all fitted with a thermometer, which must be placed level with the driver’s helmet, in the middle of the car. 

Of course, constructors could have installed this sort of equipment of their own accord. But they held back for several reasons, as Frédéric Makowiecki (#91 Porsche 911 RSR in LMGTE Pro) explains: “Air conditioning is driven by the engine. That means losing 5-6 hp, which adds on 3 or 4 tenths of a second per lap.” Mathias Beche in the #13 Vaillante Rebellion adds: “Air conditioning means extra electronics, which can impact reliability, so we use it as little as possible. It’s air conditioning, but it doesn’t mean 20°C, it’s just to keep the temperature at a reasonable level.” The 30-year-old driver particularly dreads heat: “When it’s very hot, you lose 2.5 litres of water in the first stint, so we have to drink a lot to make that up. In the next run, you lose 3 litres and as you sleep a little after that you don’t totally compensate. And so it goes on... You can’t make up for it completely. Some drivers get cramp from dehydration. I get nauseous, which means I can’t drink much. In Dubai in January, I had to be put on a drip after the race."

Water-cooled firesuits do exist, but endurance drivers don’t tend to use them. However, they do specific training to improve their resistance. Stéphane Sarrazin, who lives in the south of France, likes cycling. “I go out at the hottest time of day, around 2pm, without much to drink. It helps me get used to the heat, which is an advantage over some of my opponents.”   These guys are more than a match for the hot sun!

Photo: Porsche

These days cars are fitted with air conditioning to prevent drivers from being exposed to intense heat in the cockpit and falling unconscious, like Didier Pironi and Johnny Herbert have done in the past.