Well things are not quite so easy, for one you can insulate your house much better than your body. Passive houses for example can keep your house at a comfortab

Well things are not quite so easy, for one you can insulate your house much better than your body. Passive houses for example can keep your house at a comfortable 20 deg all year using only heat from the bodies of the inhabitants and the water heating system. One reason is, that the temperature differential between your body and the surrounding is much larger than between the house and it's surroundings, another that you have to have exchange heat (i.e. need to breath). Also how hot or cold you feel is highly dependent on what activity you do, i.e. you are likely to be much colder working on your computer than e.g. cooking. So if you adjust your temperature to the minimum for most of your activities will automatically lead to you freezing at some activities.