In the wake of last year’s Qatar Grand Prix, where drivers suffered in the heat and humidity, the FIA responded with the introduction of new rules to improve cockpit cooling.
The first step happened this year with teams allowed to add another opening on top of the chassis, so that on hot weekends the drivers could have more fresh air in the cockpit.
This was a simple solution that was also easy to adopt on the cars in the short term, while work continued at the governing body to find a more effective solution for the future.
Last November, after months of research and testing, the F1 Commission approved plans for a proper driver cooling kit.
Now, Autosport can reveal more details about the objectives, development and technical background as to how the system produced by American company Chillout Motorsports work.
The US company is involved in projects beyond racing, as its technology extends to other sectors such as medical, military, maritime, aviation and automotive.
However, it has a good motorsport pedigree, developing technology to manage the temperature of Formula E batteries during recharging, as well as solutions to improve driver cooling for various categories such as the WEC and NASCAR.
Making a system for F1
The development of a system suitable for F1 began between early last year when Chillout Motorsports was approached by the FIA to see if its system could be adapted for F1.
Its technology, called Cypher Pro Micro Cooler, would have to be redesigned and miniaturised to adapt to the demands of grand prix racing.
The cooling system that will be seen on the cars is made up of two main elements: a box, where the miniaturised components (a micro-compressor, an evaporator and a condensation unit) are located to keep the liquid cool, plus a fireproof T-shirt to be worn by drivers under their suit (see above images).
On the shirt are a series of tubes, about 48 metres long in total and arranged in such a way as to wrap around the driver's chest and back. These tubes are connected to the box, so the fluid (a mixture of air, water or a solution of sodium chloride, potassium chloride or propylene glycol) will flow to cool the driver.
As explained by Charles Kline, the company's founder, the most complex part involved the certification of the flame-retardant shirt since, for safety reasons, the requirements from the FIA are strict.
"Even before they reached us, we were already working on an FIA-approved version of our cooling shirt,” he told Autosport. “We have been working on it for three years. It's a really challenging project because the FIA rules are so stringent in regard to fire safety. We didn't want to just make a product that was FIA approved. We wanted one that actually was highly functional and lightweight, that drivers would still want to wear.”
This was the most complex part of the project, because the tubes had to be functional but also had to meet the fire resistance measures imposed by the FIA. This meant using four different types of material to guarantee the right conductivity, flexibility and resistance.
“That was the challenge because before there was no way to produce the shirts without doing two layers of material. So you were sandwiching the tubes in between two shirts, basically,” added Kline.
“Eventually, after years of testing hundreds of different materials, we were able to come up with a formula for our tubes that is conductive yet fire resistant and bendable at every temperature.
“It sounds easy, but the tubes get hard when they get cold, and they get too soft when they get hot. If they catch on fire, they melt.
“It seems like a very easy task, and it looks like we just have tubes sewn onto a t-shirt. But making these tubes work, plus be lightweight, comfortable, conductive and of course most important for the FIA, safe, was a complex challenge.”
An interim solution for 2025
For F1 teams, this is a completely new system, which had never previously been tested on single-seaters.
This added challenges to the project, especially since the current cars were not developed to take into account additional space for the cooling device elements. This is why a bit of imagination also had to be used to find a suitable location for the system.
The challenge for Chillout Motorsports was not so much redesigning the box containing all the necessary instrumentation to cool the liquid, but rather where to place it in the car. The box includes the same elements used in other categories, but was revised by creating a carbon fibre structure that could be adapted to the requirements of the teams. In fact, each team has different requirements and this required a great deal of collaboration, even if only to work out where to position the box.
“The cooling systems are for us very easy,” explained Kline. “The only hard part for the cooling systems is fitting them in the chassis, because teams have never had this system before.
“There's no room in these cars for anything. We're temporarily trying to find space so that they can do proper testing in the cars, behind pedal boxes, in sidepods, behind the seats, anywhere.”
At least for the first year, each team will have a solution adapted to its individual needs, which is also why the 2025 regulations provide more freedom in the positioning of the system.
The weight topic: Why the 5kg of the regulation are not 'real'
Behind the realisation of this system lies another interesting aspect: how it can be powered. This led the FIA to guarantee an increase in the minimum weight of the car by 5kg when this device is to be used.
The system itself is light, since it weighs just under 2kg, while for the mesh it adds around 300g. But the FIA’s extra 5kg allowance is related to the way the system is powered, via an external battery pack, as it was decided not to change the electric configuration of the cars until 2026.
This allowance will be changed in the future because the next generation of cars will incorporate the system from the off – and it can be powered by the car’s own systems.
How effective will the system be?
The regulations stipulate that, once the ambient temperature exceeds 30.5C, the FIA can enforce the use of the system by notifying the teams 24 hours before the start of the sprint race or race.
Considering that this will have to be done in the garages during race weekends, it will be necessary for mechanics to be able to easily install the system even between sessions, something that engineers will certainly take into account when designing the cars.
Kline added: “They need something that's not complex, and that's not going to take a lot of time. That's also why I'm looking forward to 2026, because it will be a modular installation that can be completed in a matter of minutes.”
The idea ultimately is to make two or three different versions that teams can pick from – which will help reduce costs.
Removing heat from the driver not only aims to solve the primary problem, but also helps the body itself to function better with less stress and thus should reduce errors.
Technologies such as these are also used on military jets and in astronauts' suits, to reduce the body heat and make the brain perform better, since there is no margin for error.
The system seems very simple with the cooling tubes, but it is a complex process designed around how the human body works.
“Ninety-five percent of your blood flows through the surface of your skin,” Kline explained. “The most efficient way for us to capture that heat energy, and this is why your whole body sweats, is to pull that heat away by using our shirts.
“Our shirts have about 48 metres of cooling tubes sewn onto them. The importance of that is we want to put as much surface area on your body as we can. We can't just put three or four metres of tubing in.”
The cooling also needs to be pitched at the right level, so it doesn’t make drivers too cold.
“We could run the system at 0C, but when you do that, it stops the blood flow to your skin, because your body's trying to protect itself from hypothermia. We can make the driver shiver from cold, but that's not what we're trying to do,” Kline said.
“So the trick is to make the system work the best – which is around 15C. That way it's very cold, feels amazing, but it's just before the point of where your body stops the blood flow through your skin.
“We're trying to make it more like air conditioning, where they don't think about it. They don't feel it. They're just extremely comfortable, their heart rates are decreased significantly and their breathing is slowed.
“The drivers love this system. It was great to hear one of the Ferrari drivers [Charles Leclerc] say that he wishes he could run this system in every race.”
