Jimmie Johnson, driving the No. 48 Lowe's Patriotic Chevrolet. Getty Images

A major factor in Nascar racing is keeping up with the physical demands and challenges of staying cool. Sometimes it doesn't go so well. Last September at the race in Richmond, Virginia, six-time champion Jimmie Johnson felt that first hand.

"The fans that circulate air inside the race car stopped working. I thought I was fine though, but I was climbing out of the car, I felt cramps everywhere." Johnson thought he could manage it by lying down on the ground. He spoke with CNBC on Wednesday. "That only made it worse, so I tried to stand up, but I got lightheaded—and I saw the tunnel." In his fall, he aimed for a crew member who was still kneeling on the ground, "so I didn't split my face open." After a 15-second blackout, Johnson was taken by a golf cart to the infield care center, where he was treated and released. Johnson is a triathlete, trains year-round and thought he was fine—and yet he still passed out.

You gotta be kidding me, the South is so hot and sticky Jimmie Johnson NASCAR driver

Johnson has teamed up with Mission on its line of cooling products, like that famous EnduraCool towel you've seen a lot of people using. "All you need is water in the towel and you're good to go," said Johnson. He would know, having already used the product before officially partnering up. "I found the towel at Lowe's and had it in my garage," said Johnson, who has felt a "disadvantage coming from Southern California" and moving to North Carolina. "You gotta be kidding me, the South is so hot and sticky." Tuesday, Johnson said the temperature reached 92 degrees when he went out for a run. Read More In NASCAR, separating champions from the rest

Johnson and his main sponsor Lowe's are also kicking off a heat safety awareness campaign for people across all work sites. Mission founder Josh Shaw says the multimillion-dollar campaign will include almost two months of television ads, along with events around the country. This Sunday night's Nascar race in Charlotte, North Carolina, is the longest of the season—600 miles—a full 100 miles longer than anything else drivers will see all year. Johnson has seven career wins there, and already has three wins this season. With a race this long, Johnson said the key thing will be "to make sure I get some calories in me during the course of the race."

I've challenged (Donovan McNabb) to whatever athletic endeavor he wants, but he laughs it off Jimmie Johnson NASCAR driver