What Kind Of Heat
The worst is coal. The best is none. Breathing coal fumes
during the beginning of the industrial age may have brought the
new lung diseases: tuberculosis (TB), and pneumonia. It may
also have worsened alcohol addiction (beryllium toxicity).
Choose electric heat if possible. Even though electricity is based
on other fuel consumption, you don't have to breathe those fumes
Wood stoves can be made safe by making sure the chimney
works properly. Never use a lighter fluid. Don't fill the house
with smoke when stoking.
Minimize your use of fossil fuels in every way you can.