Professional racing is an extreme sport. Drivers battle super-hot temperatures and G-forces for hours. To survive a race, let alone win one, a driver needs to be in top physical health.

A startup called MC10 based in Cambridge, Mass., is making wearable electronics that could change the way drivers train and stay on track during races. In the future, they hope to help all kinds of athletes up their game.

Through the thin plastic sensors worn on the arm like a transluscent patch, a driver's team can monitor the driver continously during a race, keeping tabs on their level of energy and hydration, fixing both car and driver at break points in the race. "Think about it as a pit stop for the driver," Ben Schlatka, MC10's cofounder and VP of business development, says. The sensors will be designed to be specific to their use, but can detect temperature, electrical signals to pick up heart, brain, and muscle activity, measure hydration levels, and even detect motion. 

MC10's sensors are made of the same materials that regular electronics are--a combination of semiconducting silicon and metal electrodes. The difference here is that these sensors have been engineered to be bendable, stretchable, light, and extremely sensitive. This makes wearing them a dramatically different experience than wearing conventional electrodes and monitors that are rigid and tough. 

"[They're] truly a soft, thin, almost skin-like device that integrates seamless with the athlete," says Schlatka. They are also built for roughness. "G-forces, temperatures--our technology will survive all of these things," he tells Fast Company. Though only about an inch long each way, the sensors can pick up hydration levels, heart rate, even motion cues.

This past weekend, MC10's sensors took their first spin in a NASCAR race, pasted to the arm of 22-year-old driver Paulie Harraka during the NASCAR Camping World Truck Series race on the Martinsville Speedway track in Ridgeway, Virginia. Early on in the race, plans veered slightly off course when the car's cooling system failed. "I was hotter than I normally am and the adhesive of the MC10 patch worked just great," Harraka tells Fast Company. 

"You're on the edge all the time," Harraka continues. "The temperature in these vehicles get up to 140 degrees. The race lasts for hours."

MC10 was spun out of materials scientist John Roger's lab at the University of Illinois, where Rogers and his team have been designing bendable, stretchable electronics that can be unobtrusively connected to the body. Members of the lab have designed sensors on flexible catheters to aid heart surgeries, eyeball cameras that augment vision, and channeled their expertise in skinny, flexible electronics into stick-on skin sensors for monitoring daily health signs. 

The company has collaborations for sophisticated medical tools underway, with partners like Massachusetts General Hospital. There they're testing out sensors attached to catheters that pick up vital signs of a patient during heart surgery. While those hi-tech medical tools make their slow journey through the FDA's regulatory process, MC10 is targeting an early adopter athlete market in parallel, racing ahead with this first collaboration with Wauter Motorsports, Harraka's team. Military applications are in the pipeline through project collaborations MC10 has in place with the U.S. government and Department of Defense. 

"Athletes are an early market segment for us because they appreciate tech that allows for performance optimization," Schlatka says. "There's no regulation, it's faster to the market." In fact, speed fiend Harraka only met the MC10 team for the first time this March, at the MIT Sloan Sports Analytics Conference in Boston. Less than a month later, he was revving up his engine with a custom-designed sensor stuck on his forearm. To Harraka, the deal made instant sense. "At NASCAR we're such a technology and numbers-driven sport," Harraka says, "it's totally natural they'd want to be using and testing cutting edge-tech." 

The race on Sunday was a demonstration that the sensors (currently inactive) were durable and would stay on during real race conditions, without distracting the driver. In the coming months, MC10 and Harraka's team will be testing multiple sensors to pick up health readings during practice runs and other races.