Seventy years ago, the power was out, but this family was safe and warm thanks to following the helpful pointers in the March 1953 issue of Popular Science. The general advice is the same–you should make some basic preparations for power outages. We’ve previously covered the subject in general, as well as specific provisions for cold weather.
If you have a gas stove today, you can (in most cases) use the burners on top if you light them with a match. But today, unless you have a very old oven with a pilot light, the article’s advice about using the oven won’t work–on modern gas stoves, the oven requires electricity to operate. And unless you have an absolutely ancient gravity furnace, it won’t work without electricity. But letting the faucets drip is still a good idea.
I wouldn’t improvise some kind of burner on your furnace, and there’s no need for an army-style stove. Today, there are safe propane and kerosene heaters certified for indoor use, as we previously reviewed.