Cabin vents blowing steam

Hey guys,

So on my drive to work yesterday about a 2 or 3 miles on the road from pulling out of my driveway, i noticed my side windows fogging up, so I turned my defrost up from Med-Low to Hi. it was dark out so I really couldnt see much and then the next thing i know about 30 seconds later i cant see out of my windsheild. I was looking for a good spot to pull over to find something inside my truck to wipe my windows off so i would not be late to work and eneded up putting the heat on my feet and driving with my front windows down the rest of the way to work (it was a long, cold 20 minutes.) The temperature outside was about 15 degrees coming from west michigan. I did everything I normally do to prepare my truck for driving in the cold after sitting outside all night in the snow. I Started it 10 minutes prior to leaving and the steam problem started happening once my engine hit about 110-120. I Initially thought I had blown my heater core but after making it into my parking low at work i didn't see or smell any antifreeze anywhere. I warmed it back up at lunch time and drove around going througha few cooling cycles heating the coolant up to around 210 degrees and there was no steam. just wondering what went wrong or if my truck just fixed itself. (I wish it always did that))