cold weather windows

Some have written that when camping in cold weather and have to use a small space heater to help even out the temps on the bed ends, the windows always tend to ice up.. ....Is that the norm? And by the way, do the TM have screens on the windows? As you can tell I don't own one YET, but I'm saving my milk money.....thanx biggfreightt

I live in California so icing up is not something Ive experienced. They do get condensation if everything is closed up at night. And yes, they have screens.
Cheri

Just for clarification most use electic "cube" heaters to use the campground electricity for heat instead of their propane. a few will use a heater in the rear bed area to "equalize heat". I have been down to 18F in our TM and had condensation at the endcaps freeze but never the moisture on the window....I guess it could if it got real cold but hasn't happened yet.

Bill