The prohibition was implemented in the World Endurance Championship last year but lifted for the French classic after a chilly Spa-Francorchamps round was the scene of several crashes on cold tyres, including Toyota's Brendon Hartley at Raidillon in qualifying and Ferrari's Antonio Fuoco mere seconds after leaving the pits in the race.
Although another U-turn was considered for 2024, the ban remains in place this week at Circuit de la Sarthe, where temperatures are not be particularly warm to make up for it – they are in line with the 1991-2020 weather data, dipping close to 10°C (50°F) at night.
Going out on track with cold tyres is therefore not be something drivers look forward to.
"Overall, it's like driving on black ice. It's very similar," Porsche's Frederic Makowiecki describes. "You get there, you're turning, it won't turn, the car goes straight; you're braking, it doesn't brake.
"On top of it, the current cars with many systems react even more unpredictably."
Peugeot driver Loic Duval explains: "You know this feeling when you're on a plane, there is big turbulence, and at some point there's an air pocket. Woah! It's similar for us.
"When you lose it, that's the feeling – and you lose it quite a few times in the first two laps! As long as you don't go off, good. Then if you go off, you look like an idiot."
The nocturnal practice sessions in particular are important to apprehend the situation, with two-hour running from 10pm to midnight on both Wednesday and Thursday.
"We know that we have a soft that works really well in those conditions, especially in terms of warm-up", Makowiecki points out.
Toyota's Sebastien Buemi clarifies: "The issue is that the soft tyres are quite good in terms of warm-up, but once they are hot, they are too soft – so the car moves a lot, and it's not really good.
"So at some point, you may take the risk to go with the mediums, but the mediums are really hard to switch on. And if it's cold, you may have something like we had in Spa last year."
Makowiecki points out that on a "warm" Test Day – with temperatures ranging from 16°C to 23°C – it took only "half a lap" to bring a set of medium rubber up to its working window.
Yet, Buemi remains worried, especially regarding traffic: "It's clear that when you get out of the box and you're on cold tyres and someone comes with warm tyres, it's a huge difference in the first sector. It's massive. Sector 1 with cold tyres, you are seconds and seconds off."
"When you have a car coming out and being five to ten seconds too slow in Sector 1, you know, it’s a chicane – you have an extra corner on the track! Of course, it's going to create potentially some weird situations, where you have a GT that arrives into Turn 1 and is way faster than you in the first sector – even though he's driving a GT."
The reason stated for the tyre warmer ban is ecological, although Duval questions the actual gain from the "radical" measure, for instance if it leads to crashes pushing teams to produce more spare parts. The French veteran however insists he's aware that the sport remains a technological "laboratory" and suggests a different, better solution could potentially be found.
Meanwhile, a lone voice arises in Kamui Kobayashi, who clearly relishes the difficulties posed by cold tyres.
"You don't need to ask this," the Toyota team principal and driver retorts when Motorsport.com mentions the lack of tyre warmers.
"We are paid for this, as a professional driver – any situation, even really bad conditions in terms of weather, like last year in the night.
"We need to survive, this is our job. I think the challenge is more for the amateur drivers.
"If whoever can do it, we don't say 'professional racing driver'. [The ban] is welcome, to be honest."
