The origin of the cooling shirt in NASCAR racing was initially something of a puzzle. Many drivers weren`t sure how it first appeared in the sport. Some speculated it came from Hendrick Motorsports, perhaps specifically linked to Jimmie Johnson, known for his pioneering approach to fitness and performance.
“I was the first driver to use one,” Johnson confirmed, “but credit for initiating it goes to Chad Knaus.”
Johnson explained that his crew chief, Chad Knaus, was always exploring new technologies and held a comprehensive view of performance enhancement, which included focusing on Johnson`s physical condition. As a driver prone to cramping and heat-related issues, Johnson was a prime candidate for exploring cooling solutions. Knaus acquired a cooling shirt and decided to rigorously test its effectiveness.
Johnson recounted the unique testing method: “Back when we used to paint the cars, one of the bays could be heated to 100 degrees to speed up paint curing. [Knaus] literally sent one of our crew guys into this heated bay wearing the shirt, plugged it in, and had him sit there simulating being in a race car to test it. I distinctly remember Chad calling me, `You won`t believe it, this cool shirt thing actually works! I`ve got so-and-so in the spray bake booth, I`m roasting him in there, and he has the shirt on and feels great!`”
Johnson started wearing the shirt around 2018 or 2019. Initially, it was a closely guarded secret known only to his team, as he viewed it as a competitive advantage. However, as its existence became public, other drivers quickly followed Johnson`s lead, in a classic case of “monkey-see-monkey-do.”
Joey Logano describes the experience with a characteristic big smile and laugh. “It`s like jumping into a pool on a hot summer day,” the champion driver remarked. “It feels incredible. It`s amazing.”
Simply put, a cooling shirt is a garment embedded with tubes that circulate cold fluid, dramatically improving driver comfort in extreme heat.
“I recall years ago using ice packs in our suits and swapping them out during pit stops,” said Erik Jones. “On a hot day, for endurance, it`s a total game changer. There were days after scorching races when you were just completely spent, regardless of your training level. This technology has changed things so that even if it`s 90 degrees outside, drivers aren`t really worried about the heat inside the car anymore.”
Driver cooling techniques have progressed significantly over time. Past methods included ice packs, fans, and helmet hoses delivering cool air (the latter is still used for head cooling). However, these don`t compare to the full-body surface cooling provided by the shirt. Today, it`s difficult to find a driver in the field who doesn`t utilize one.
Erik Jones isn`t alone in calling the cooling shirt a “game changer.” Michael McDowell noted that the increased adoption rate coincided with the introduction of the Next Gen car in 2022. Teams quickly discovered during testing how much hotter these new cars ran, making the cooling shirts far more appealing.
“[The shirts] were around before, but they often failed or weren`t very cold,” McDowell explained. “You hesitated to rely on them because you didn`t know if they`d work properly that day. But now, although there are still occasional issues, wow, it`s unbelievable how much it helps keep your core cool, protecting vital organs and significantly lowering your heart rate by taking away some of that heat.”
Some drivers, like Shane van Gisbergen, even freeze their shirts beforehand for maximum cooling effect. This ritual is so crucial that his PR representative has a recurring calendar reminder: “put cool shirt in freezer an hour and a half before the drivers` meeting.”
Not all drivers wear the shirt every race weekend; some decide based on the weather conditions. Ross Chastain is one such driver, mentioning there are times he prefers to sweat naturally. “At Martinsville, I actually had to use the bathroom because I wasn`t sweating enough,” he quipped.
When worn in the car, the shirt (or vest, depending on preference) under the firesuit connects to a pump. Cesar Villanueva, Kyle Larson`s interior specialist, noted that the pump can be positioned flexibly within the cockpit.
The pump circulates a mix of water and an antibacterial/antifungal fluid. This mixture is vital for keeping the system clean; without regular circulation, it can clog, preventing the pump from running. However, pump failure isn`t the only way the system can let a driver down during a race.
“You`re simply stuck in a difficult situation,” Austin Dillon commented on system failure. “There`s not much you can do except turn it off. You can dump the water if possible, but it feels like losing a lifeline. Having it work is pretty essential.”
If the system fails, especially if the fluid can`t be drained, the driver essentially starts overheating. The fluids become hot, offering no relief.
“It`s fantastic until it`s not,” Logano summarized. “But most of the time, it is fantastic. Honestly, they`ve significantly improved the entire system`s design. It used to be quite heavy, which deterred many from using it. Now, the process is quite efficient. If it helps you mentally stay sharp at the end of a race because you`re physically less drained, you`re going to use it.”
“It doesn`t matter how fit you are, you`ll experience fatigue after 400 or 500 miles,” he added. “If you can maintain a bit more freshness, it`s probably worth the trade-off.”
Naturally, weight is a significant consideration. Driver comfort is crucial, but so is car performance, and extra weight costs valuable lap time. Despite this, the performance impact necessitates accepting the weight penalty, which Villanueva estimated at around 6.5 to 7 pounds for the unit.
“I believe we`ve accepted some of the weight disadvantage from wearing it,” Chris Buescher stated, “because you absolutely need to be as fresh as possible to compete effectively at the conclusion of these long races.”
Tyler Reddick started using a cooling shirt in 2021 after losing weight. He found he suddenly needed something to better regulate his core temperature because he felt himself overheating much faster without his previous `insulation.`
Reddick`s assessment perfectly encapsulates the significance of the cooling shirt in NASCAR today. “A lot of drivers use it,” he concluded. “I think what it achieves for cooling the body is likely the most efficient method we have available.”
Dominic Ashworth