Garage heater affect painting?

Will using a propane, Natural Gas, or Kerosene heater in the garage affect the quality of painting results? I wonder about potential added moisture in the air. It's getting below 50 now and I have some frame stuff to prime and paint as well as needing to prime as I do bodywork over the winter. I have a small electric heater which gets me to about 50 degrees but will have to use additional heater to get it warmer where the paint/primer will cure. I won't be doing any finish painting but will want to have solid results so I don't have to redo anything before final.