EE TRAVELING N. ON SR 301 HEARD NOISE & FELT SOME VIBRATION UNDER THE TRUCK. HE STOPPED TRUCK ONSIDE OF ROAD. AS HE EXITED THE TRUCK, FLAMES WERE COMING FROM UNDERNEATH. FLAMES WERE EXTINGUISH ED WITH NO FURTHER INCIDENT. HE WAS TRANSPORTED TO PLANT MEDICAL FOR CHECKUP. HE HAD QUARTER SIZED BLISTER ON TOP OF INSTEP, WHICH WAS CLASSIFIED AS A SECOND DEGREE BURN. OTC MEDICATION GIVEN