As I was driving down the road I began I started to smell something unusual - in a way it smelled like burning plastic and/or anti-freeze. I then began to feel quite a bit more heat than usual on my lower back, so much I knew something was wrong. I pulled my truck over, got out and as soon as I got out my heated seat started producing smoke where I believe the main heated seat coil is. Within seconds a flame burst out from the seat. I luckily had a drink in my cup holder that I reached over to grab & pour out on the flame. It kept smoking after I dumped the liquid on it. I then grabbed a water bottle from my back seat & was able to put the fire out completely. In conclusion, my 2019 Ford Ranger Lariat Crew Cab heated seat caught fire while it was turned on, on 9/15/2022 at approx. 9:00a.