December 14, 2015 around 6:40pm i was driving home from work on highway 275e at approximately 70 mph approaching the 71n exit ramp . car and driver's seat heater had been running about 8 - 10 minutes. i smelled a burning smell. i was wearing jeans. when looking around to figure out where smell was coming from, my left leg came in contact with seat, i felt a "bite" sensation on the back of my leg - immediately i thought perhaps my seat was was on fire. i didn't see any actually flames, so i turned off seat heater, and opened the windows - hoping to cool off the interior of the car to prevent any smoldering in the seat to advance to a fire (sounds a stupid now, but at the time it seemed to make sense). continue driving with one hand, windows down, and fanning seat with the other. with the windows down, the smoke/burning smell dissipated. by the time i got home (about another 10-15 minute drive from the initial occurrence), the seat had cooled. i observed a burn spot on driver's seat where i felt the "bite" on the back of my leg. i also thought my jeans were burnt; however, that turned out to be transfer from the burnt material from the seat - i was able to scratch most of it off with fingernail. also, my skin was not injured. i will be contacting my local mazda dealership today.