Every year out here as soon as it starts getting cold, we have the woodstove police start monitoring air quality, and when they think conditions are right, they declare a burn ban. There are supposed to be two stages of burn bans, but last Friday around 4:00 the Southwest Washington Clean Air Agency went right straight to a Stage II ban and it has been in effect ever since.
You are still allowed to heat with firewood in Washington. When the temps get down into the twenties at night, a heat pump becomes just about useless and you have to have a secondary source of heat. In forced air systems, the "emergency heat" is electric coils in the system and it is about the most expensive way to heat your home I know of. But if I turn the heatpump off and use the forced air to circulate the heat we can keep the whole house nice and toasty for a fraction of what it would cost to even try and use the heatpump.
Last January I finally had to send these people a letter threatening to sue them for harassment because I have one crazy neighbor who cannot stand the fact that I "murder trees" and use them to heat my home, and she calls in repeated anonymous complaints about our stove as soon as she sees a burn ban in place. The Agency accepts anonymous complaints, even repeat anonymous complaints about the same address. The legislature has even given them authority to write $125 citations, but I have not heard of one being written around here yet, and if they send one to me my lawyer is ready to shove it where the sun does not shine.
But that's what it takes these days to protect yourself from harassment over a 100% legal activity as simple as heating the house in cold weather.