For the first time in 2026, the Formula One teams will have to cope with tropical conditions across the weekend of the Miami Grand Prix. To this end, the FIA has introduced an additional set of last-minute regulations just hours before the cars take to the circuit outside the Hard Rock Stadium.
Temperatures are expected to soar on Friday and Saturday and trigger the FIA’s official definition of a “heat hazard.” This is when ambient temperatures rise above 31°C, meaning the teams must fit additional hardware to the car to handle cockpit cooling.
For 2026, the core components of the cooling system—the micro-processor, pump, and heat exchanger—must be integrated into the car’s electrical architecture and be present regardless of whether the driver uses them or not.
Wear the cooling vest, or suffer ballast penalty
The drivers can choose whether they wear the actual liquid-cooled vest, although should they not do so, they will be hit with a 0.5kg ballast penalty placed within the area of the cockpit. This ensures a driver rejecting the cooling vest does not gain a weight advantage.
The vest features a remarkable 50m of micro-tubing woven into the fireproof undergarments. It circulates chilled fluid to cool the driver, although in 2025, both Max Verstappen and Charles Leclerc claimed that when it fails, it then acts like a hot water bottle.
Friday and Saturday in South Florida are set to hit temperatures of 33°C, and the FIA will declare a heat hazard. For Sunday, slightly cooler climes are expected in the late 20s, and so the vests may not be required. For Sunday, however, storm conditions are forecast, including torrential rain and possible thunder and lightning.
Regulations in the USA mean for an outdoor sporting occasion, if lightning is detected within ten miles of the event, it must be paused or cancelled should the conditions persist. The forecast rain will be the first time the all-new 2026 cars and their power units will run in such conditions and, late in the day, the FIA believes incremental safety rules should be introduced.
Electrical boost disabled in the wet
In what race control deems “low grip conditions,” there will be a complete ban on the use of the electrical boost mode during rainy conditions. This function allows the drivers access to an instant 350kW of additional battery power when racing, but the nature of the torque deployment is now of concern.
Unlike an internal combustion engine, torque (twisting power for the axle) is instant from electrical motors and so, as the grip lowers, the cars become more difficult to drive. At the season opener in Australia, McLaren’s Oscar Piastri suffered an unexpected electrical torque spike on his way to the grid, which sent him spinning into the barrier.
Given the rains are expected shortly after the race start scheduled for 16:00 local time, fans may once again get to see the chaotic start in dry conditions the new 2026 power unit designs have brought about.
However, as the rains arrive, not only will the boost mode be disabled, but the low-drag “straight mode” for the aerodynamics package will also be restricted. Only “partial activation” of the straight-line mode will be allowed, forcing the drivers to carry more downforce to create more grip.
Active aerodynamics also “partially restricted”
The downside, of course, is that drag is increased, meaning the top speeds of the cars will be very much restricted. The cold front from the north of Florida is being tracked daily by US weather forecasters and will at some point arrive in Miami.
During the running of the 2025 Daytona 500, a similar cold front arrived from the north, which meant the racing was suspended for more than three hours—by which time most fans had left the track and gone home.
Formula One will not have such a window to complete any storm-affected race on Sunday, given time limits were brought in following a four-hour-plus Grand Prix at the 2011 Canadian Grand Prix. Now, the total length of time allowed to complete the race while the cars are on track is two hours.
At the two-hour limit, the next lap the leader starts becomes the final one of the race. Further, to assist broadcasters in their scheduling, a three-hour maximum window is also imposed from the moment the race starts to when the checkered flag may fall.
Heat has been Mercedes’ achilles heel
This is to allow some time for red flag incidents and was reduced from four hours to three hours following the 2021 Belgian Grand Prix. Fans and broadcasters were forced to wait out four hours with just two laps of action before the event was inevitably and finally called off.
With the F1 circus attending its first tropical venue, there will be a huge amount of interest in whether the hot temperatures affect certain teams more than others. Despite their current dominance, in recent years, Mercedes F1 car designs have not coped well with high track temperatures—which will reach around 50°C in Miami this weekend.
Their car designs often are focused on a precise front end which can make the car “pointy,” which in hot conditions forces the rear of the car to slide more than usual. This has been because their rear suspension is often sprung to the maximum stiffness to improve downforce, but it has the result of hammering the tyres into the tarmac, causing them to “cook.”
Of course, for 2026, ground effect has gone and, along with it, some of the need for a stiffly sprung rear end of the car. Yet with no hot weather running to date, it’s difficult to understand which F1 car designs will work well or be compromised in stifling conditions.
Ferrari class of the field with cooling packaging
Yet the heat will affect the cars significantly as well as the tyres, and there was some evidence in Japan that Mercedes’ ultra-tight aerodynamic packaging was causing the hybrid to reach its thermal limitations.
Ferrari appears to be class-leading in terms of their heat management; using a steel alloy cylinder head allows for much higher operating temperatures without reliability loss. Audi, too, had heat management on their mind when they designed a radical “high inlet” sidepod which focuses on clean air intake to protect their 350kW battery from overheating.
It could be a long weekend for Aston Martin, who have finished just one of the three Grand Prix they started this season. The AMR26 was seen running “emergency gills” during the pre-season testing, suggesting the Honda power unit requires more airflow than the slim packaging of the car’s design provides.
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A.J. Hunt is Senior Editor at TJ13, where Andrew oversees editorial standards and contributes to the site’s Formula 1 coverage. A career journalist with experience in both print and digital sports media, Andrew trained in investigative journalism and has written for a range of European sports outlets.
At TJ13, Andrew plays a central role in shaping the site’s output, working across breaking news, analysis, and long-form features. Andrew’s responsibilities include fact-checking, refining editorial structure, and ensuring consistency in reporting across a fast-moving news cycle.
Andrew’s work focuses particularly on the intersection of Formula 1 politics, regulation, and team strategy. Andrew closely follows developments involving the FIA, team leadership, and driver market dynamics, helping to provide context behind the sport’s biggest stories.
With experience covering multiple seasons of Formula 1’s modern hybrid era, Andrew has developed a detailed understanding of how regulatory changes and competitive shifts influence the grid. Andrew’s editorial approach prioritises clarity and context, aiming to help readers navigate complex developments within the sport.
In addition to editorial duties, Andrew is particularly interested in how media narratives shape fan perception of Formula 1, and how reporting can balance speed with accuracy in an increasingly digital news environment.
