The whole house

If the house has been built for a long time, and ordinary logs served as building materials, there will be only one way out — insulation.

The most cold in the house is the floor, therefore, at first, it is necessary to eliminate all the available cracks. Then heat it with polystyrene foam, plywood sheets are placed on top, I can also use OBS slabs, and in the end, cover with linoleum or laminate. If after that nothing has changed towards warming, you need to warm the whole house from the inside.