As I was driving my truck today I suddenly noticed a smell like antifreeze and saw it dripping on the floor board. Later on that evening while driving the temperature started to rise to about 225 degrees and than smoke started coming out of the vents. Does anyone know if this is the heater coil or what and how to fix it?

 

That's exactly what it sounds like. Plus if you loss enough coolant to cause overheating, that carpet is probably really soaked. The "smoke" is usually "vapors" emitting from off the heater coil up throught the vents. heater coils around $100. Changing them out, another story. They can be bypassed, but then you have no heat or defrost.....