Your answer was:
"Heat pumps are not designed to heat in sub-freezing temps. You may have supplemental resistance heating elements inside your air handler. Yes turn them on, but you won't achieve a comfortable temperature."
My new question is about your statement that I "won't achieve a comfortable temperature." I am confused because I have a comfortable temperature now, but the fan outside the house runs almost constatntly in the cold weather. All I really want to do is stop the fan from running outside the house during the cold weather. By turning on the "emergency heat" button on the thermostat, doesn't that just shut of the heat pump fan outside the house and kick on the supplemental heating elements? I don't understand why you say that I won't achieve a comfortable temerature, because I already have one now even though the heat pump isn't doing me any good in the cold weather. There is clearly something I don't understand. I appreciate your expert advice. Your help is appreciated.