I work as a wilderness safari guide here in Finnish Lapland, often going on trips in well below -30c and we always run fires. In fact here in Finland that is considered the ecological thing to do as it is a renewable energy source with the woods here(this does not apply however to the northernmost arctic tundra areas where trees take decades to grow!) in the southern Lapland area(we are based in Rovaniemi, Kittila, Saariselka and other places in between those mentioned). If an open fire is not enough the fire just may not be big enough...i have run fires in the open that were hot enough to strip down to just the long johns while sitting next to it in minus 34 degrees celsius. Mind you we always run groups, tho a group can be anything from 1 client + 1 guide to 1000+ clients and well over a 100 guides plus auxiliary staff(sizes and guide to clients ratios differ depending on the groups and activities). We run them during the entire season, from December until the beginning of April, offering anything from short few hour trips to multi day trips. And we do all cooking and heating by wood fire, we carry it with us. Forage is less of what we do, but we do on some longer trips(it is legal to forage fallen wood on any land, but illegal to fell wood on land you do not have specific permission to do so, and besides the fresh cut wood is useless as a fuel) and sometimes we can do logistics ahead of time and have wood already on site before the groups get there.
If you are dressed well enough it can feel good enough for warmth but sitting around is detrimental to your circulation and thus core warmth, gathering wood or doing some activities to get everything flowing is beneficial. Just layer clothes so that you can start stripping layers as needed during the activities.
The psychological effect of a fire(even one not big enough to heat you up) is underrated, it makes as much of a psychological impact as getting the warm sun on your face during a snowy early spring day and can make you stop believing you are freezing your bottom off, which often is the biggest problem since not everyone has the mindset needed to survive in such cold climates.
And as a side effect fire will repel predators here in the arctic, such as wolves, lynx and wolverines(the bears are the only ones sensible enough to sleep the winter off).
If on long trips setting up a traditional Finnish kota(a teepee type tent) with a fire running in the center works nice and many smaller groups/locals use the open Finnish laavu even during the coldest of days by running a fire right in front of the opening of the laavu to heat it up(not doable in a tent unless it is made from fire retarded materials and even then being very careful). We also use wooden grill huts/kotas that have a fireplace in the centre and seating/sleeping benches around the circle and heat it with wood. That makes for a very warm and cozy night even on the most brutally cold nights.
So far the cold record here is -52 celsius(december 1999), i am hoping to see that fall one day(soon!)
And as i often like to tell people: Surviving harsh environments is 80 percent mental. Unless you are an idiot. Then it is 100 percent fatal.
Not burning much if any wood is our choice and not his dictate.
