[auntjemima]

Leaving snow on the floors? Wet floors? Humidity inside causes your problem.

 

[auntjemima]

That's because of the wet floor. When running your heat on the drive to work you need to set it on a floor setting, either by itself or with the defroster setting. The AC was mentioned above because you can run the AC while your heat is on and it won't run cold. AC doesn't "blow cold" anyways, it removes moisture from the air.

 

[auntjemima]

As Tony said, your problem is body heat. I always have to turn on the defrost until the car heats up.