Firewood is an important resource in Banished. To get firewood, just clearing trees isn’t enough. You need to make sure that your city has a Wood Cutter. The Wood Cutter is a building which can be placed from the resource production tab (F8 and then 1 for the Wood Cutter). Once the woodcutter has been built, you’ll need to assign a citizen to it through the jobs panel. (F2 for jobs and then 4 for the Professions panel.)
The wood cutter (citizen) will turn wooden logs into firewood which will be burned by other citizens to keep their houses warm. Building stone houses instead of wooden houses will reduce your citizens’ need for firewood.
How To Get More Firewood (Citizens Are Freezing!)
If you’re running low on firewood, you can try two things. 1) Increasing production at your wood cutter. It’s possible that your wood cutter is stopping before you have enough to last the winter. Or 2) ensuring that you have more logs to turn into fire wood. Once you’re past the initial tree clearing stage of the game, you’ll need to set up Forester Lodges (F8 and then 2 for the Forester Lodge). Forester lodges ensure a steady supply of wood logs which can be turned into firewood by the wood cutter.