dirt floors

I'm curious about dirt floors and how they hold up and hold heat in a cold climate.

1)  If there is good heat in a room that has a hardwood floor built over hard-packed soil, but is not insulated, will the floor be like ice in a northern winter like it is for a cement floor?  The heat is coming through the ducts in the ceilling of the room. 

I'm curious as to whether such a space could be used for movement classes with bare feet or lying on the floor in the winter.  I'm also curious in a similar vein, if a yurt were on a raised floor over packed earth rather than on a platform. 

2)  Are there any issues that I should be aware of?  It seems to be mold free and dry, but I'm not sure about insect/bug issues, etc.

Please share if you are experienced with this type of floor.
Thank you!

Yeah, I'm very interested in this.  Can anybody help us out?  Anybody?

For many years we had a packed earth floor in our underground house. That was covered with 6 mil plastic, then wall to wall carpet.

It was OK until one year we had an incredible deluge of rain that wiped out our road and flooded the creeks. Even though we were on a steep hill, water was able to get in. It came down the underground walls and up under the edges of the walls, flooding the house and ruining the carpet.

At that point I insisted on raised wooden floors. We did 6 mil plastic covered by a cedar lumber grid. We used foam insulation between the grid, then covered the floor with plywood and carpet.

Even though the packed earth floor was OK, the insulated floor was a heck of a lot better and warmer when put over the packed earth. I lived in that house for 18 years.

I was under the impression that you could utilize earth by making cob and then adding some other materials (I believe linseed oil) to make it resistant to water, bugs, wear, etc. I may be mistaken.