Re-insulate if your home gets too cold (or hot). Insulation is there, above all, to keep your home comfortable when temperatures outside are anything but. The role of insulation is to prevent a phenomenon known as heat transfer, the process in which heat is dissipated towards colder areas. That means in the wintertime, the heat in your house is trying to get outside, while in the summertime, the heat from outside is trying to enter your air-conditioned home.