We had a brief (48 hours) cold snap here in Lafayette.
It actually got colder than indicated; I think it hit -21 at some point that night.
The night before the cold snap hit, it got down to about 9 above. Our heat pump kept up with the temperature but it never quit running that night. So I switched it to emergency heat, which worked pretty well even at the coldest point outside.
I think our heat pump is scaring our neighbor. Every so often, the heat pump will switch to defrost mode, basically reversing itself to run hot fluid through the pump to melt any accumulated ice. When it defrosts, you’ll see steam rising from the pump, sometimes a lot of steam if it is really iced over. The night before I switched it to emergency heat, our neighbor walked from his front door to our heat pump (I could see the tracks in the snow). I think they’re seeing the steam and thinking it’s on fire or something; can’t say I blame them, as I was concerned when I first saw it after buying the house! *laughs!*