DAYTONA BEACH, Fla. - Patrick Carpentier carried an oversized bottle of water for more than three hours before getting into his No. 36 Toyota on Thursday to practice for the Coke Zero 400 at Daytona International Speedway.

He has lived in Las Vegas for years and is used to heat, but nothing prepared him for the humidity of sunny Florida in July.

"I don't like this," Carpentier said. "This is miserable. I'm used to heat, but it's a dry heat. Don't laugh; there's a difference between dry heat and wet heat. This is hot."

Carpentier, like the other drivers at the track for tonight's Subway Jalapeno 250 for the Nationwide Series and the Coke Zero 400 on Saturday for the Sprint Cup Series, has spent days trying to drink as much water as possible to get ready for the 90-degree temperatures - and 60-percent humidity with a heat index of 97 degrees.

Thirteen drivers will race in both races and Kyle Busch and Scott Speed plan to compete in Saturday afternoon's Brumos Porsche 250 for the Grand American Sports Car Series.

If the Nationwide race is postponed by weather - there's a 30-percent chance of thunderstorms - Daytona plans to move the start to Saturday morning.

"You can't get ready for that," Busch said of the prospects of running three races in a 13-hour stretch. "I was hydrating myself (Tuesday) for today. I will hydrate myself (Wednesday) for tomorrow, and I will hydrate myself (today) for Saturday. But if they moved the sports car race back to Sunday, that wouldn't hurt my feelings."

Ryan Newman said he will drink 120 ounces of water and Gatorade in the day leading up to Saturday's race. He will drink about 40 ounces during the race, and 120 ounces after the race.

"And I won't go to the bathroom until the next day because it takes my body that long get back to normal," he said.

Driver Darren Law of the Brumos Racing team, said Busch's toughest challenge will be in the 2¸-hour sports car race that stars at 2 p.m. Saturday.

"Those cars are sealed up pretty tight," he said. "There is no air inside that car. When you get out of one of these cars, you're drained."

When Busch, 23, gets out, he still has another 400 miles of racing left that night.

"We'll have fun doing it," Busch said. "I'd do it if I were 40, so it doesn't matter. To me it should be exciting, I guess."

With the heat index approaching 100 degrees at race time, Newman said it's worse inside the car. He said it will be about 130 degrees in the driver's seat and 140 on the floorboard.

"I had to get different shoes because it kept burning through my other shoes," he said.