What are some ways to insulate a concrete slab type foundation in an older home built in the 50's? The slab as far as I can tell is not insulated at all and results in a very cold floor and living environment on the first level of the house in the colder seasons?

Has anyone used ceramic insulating paint applied to the top of the slab in these circumstances?

What are some ways to insulate a concrete slab type foundation in an older home built in the 1950's? As far as I can tell, the slab is not insulated at all and results in a very cold floor and living environment on the first level of the house in the colder seasons.

Has anyone used ceramic insulating paint applied to the top of the slab in these circumstances?