Motor racing-F1 champion Button feels the heat on NASCAR debut

FILE PHOTO: Formula One - F1 - Malaysia Grand Prix - Sepang, Malaysia - 1/10/16 McLaren's Jenson Button of Britain waves after qualifying session. REUTERS/Edgar Su

(Reuters) - Former Formula One world champion Jenson Button said that he suffered heat exhaustion and nearly retired from the race before finishing 18th at his NASCAR debut in Texas on Sunday.

The 43-year-old Briton, who won the F1 world championship in 2009, said he feared fainting while driving his Ford Mustang during the 68-lap race at the Circuit of the Americas.