As the cold wave hits next week with -20 Celsius temps, a good way to heat the survival room (kitchen) in case of power loss, is to invert a steel colander on the stove flame, very fast and effective heating of a medium sized room. Be careful of ventilation and carbon monoxide even though one burner risk is very low
Maybe you would like to check out a sand battery.
They’re being used now to heat entire towns for months in the winter, it can be scaled back for home use.
A little ingenuity and the possibilities are endless.
Sleeping on an electric heating blanket is also a great source of emergency heat.
It’s cheap to use as well.
What I used to do was lay the heating blanket on the bed, a sleeping bag over that, and a few blankets to cover the whole thing.
I’d crawl inside the sleeping bag, and the heating blanket would warm the whole setup.