As others mentioned this is a normal reaction to cold, warm and humidity. If it isn't raining outside you can open a vent and run the fan for a while. If it is raining or you are in a humid climate we found you will bring in more moisture than you are trying to expel. Running the propane furnace will dry out the air too so you might run it for a while.
A lot of condensation should be wiped up because some of it could run down the wall. Also be sure your window weep holes are clean and clear so that water will drain to the outside it gets into the window tracks.
Cooking, showers and people breathing add moisture so if the conditions is not remedied by venting and running the furnace and you'll be in these damp conditions long I'd consider purchasing a dehumidifier.