Clear water under car?...

[Hoosier]

The 50 degree day we had here in Indiana a few days ago was too tempting to pass up. I put the top down and my daughter and I took a spin into town around the traffice circle at the center of town and back - about a 20 mile trip. She was cold so I cranked the auto heat control up to 80 and let it blow on her feet and that did the job taking off the chill. Here's the rub: When I pulled in the garage I noticed a pool of water under the car, pretty much in the center but closer to front of car than the rear. It was dripping from the underside of the body. I smelled and inspected it and it was clear water, not at all coolant or oil. No idea what it was. No water inside on the carpet either and no idiot lights were on. The first thing it reminded me of was the condensation that comes from the A/C evaporator in the summer when the A/C runs and drips on the pavement. I did not have the A/C on though. Could it possibly be the same phenomenom related to using the heater????? or any other ideas???? Oh, it was not raining and the roads were dry. Thanks!