This is scary stuff ... NASCAR driver Denny Hamlin fell ill while behind the wheel of his #11 car during a race at Dover on Monday when carbon monoxide gas began seeping inside of his ride.
The 38-year-old says he felt sick and experienced double vision and was treated by medical staff on pit road after he finished the race in 21st place.
.@dennyhamlin was being attended to by medical staff on pit road once he exited his car. Looked exhausted.
He was seen on a golf cart being wheeled away for further treatment.