Have your chickens had time to acclimate to those temps? I don't worry here about cold temps. Mine got by last year with those below 20 temps that we rarely have and they were in a prefab and no heat.
I’m not sure... being as we have been hot (no fall at all!) and now we are freezing! They seem totally fine... it almost seems they are happier in the cold than the hot
). I only intervene in cases that I've found it to be necessary--a bird that's ill, injured, or otherwise not acting right, in a heavy molt (such as Tessa), or very young (say, less than 3 months old). In such cases, I never add heat to the entire flock, but instead move individual birds to a location where they can be provided heat individually. I would suggest you take a look through one of the articles I've written discussing the many adaptations that these birds have for cold weather. As you've observed, they seem to like colder weather much better than they do hot weather. It's much easier for them to keep warm than it is for them to cool off in high heat because of the structure of their feathering. There are exceptions, of course, and extreme temperatures at which intervention may become necessary, but I don't think you'll see anything low enough to warrant such action where you live. 
Great... thank you so much! Yes, they were not happy with that red “sun” shining in their bedroom window.. they kept going up.. looking in then going back down.. wondering why it was light INSIDE but dark outOh, no, no heat needed at those temps! My birds have seen temps as low as -20° F without issue. Not even frostbite (except a few comb tips, though one was because she liked to dunk her comb in the water bucket
https://www.backyardchickens.com/ar...k-at-the-question-of-supplemental-heat.67147/
P.S. If you do decide to heat after all, I would strongly suggest you switch out the heat lamp for something else. Not only are large heat bulbs a big fire hazard, but continuous light (yes, even the supposedly superior red lights) is very unhealthy for these birds. There are heating plates specifically for chicken coops, plus ceramic bulbs that emit heat without light that would work well for the job as well.
Boys like that around here would have a space in the freezer with their names on it. I know people say they can be trained, but I've never had success, even following rooster training advice to the word. I can't have boys that I can't trust enough to turn my back to, not with my niece and nephew running around out there all the time. Not that that helps you, since they aren't your boys. 
Sorry about the bruises, and fingers crossed for good weather for you to get home, Shadow Rabbit! 
We got maybe a dusting of snow (it's in patches and less than one inch deep at the deepest), then freezing rain over top of that. Yuck! Despite how shallow it is (and hard, so you can walk on top of it), the girls are refusing to leave the deck today. Oh, well! I'll be watching them very closely for another week, just to be safe.
Yeah, it seems like a lot of production-oriented lines have issues with aggression, especially the roosters. What breeds do they keep where you work? I think Tessa went the same way as her this year--poor girl was a pin cushion! She's looking quite sharp now. I'll have to get an update picture of her. 
