warm blankets may be nice, but really, there are quite a few very basic ways to do that, my grandma had a little metal tank, heated up and filled with boiling water to heat up the beds in her house, which even a decade ago only had two rooms with a fire oven, so in the winter the bedrooms were not really warm, but with that you could go inside a warm, cozy bed, here with a oven inside her room, there is no way, that it's that cold
she really should have invented something else