The 8-year-old boy grabbed the wheel of his grandma's pickup when she suffered a seizure.
The boy was able to guide the truck to a stop on I-70 in the Grand Junction, Colorado, area.
Authorities say the pickup was going about 75 at the time.
Dillon says he pushed on the brake and steered the truck toward the side of the interstate.
His grandmother, Lisa DeKruger, is recovering.