We heat with wood and save as much of it as possible for the coldest winter nights, which even with our best efforts result in mornings in the 40 degree F range in some areas of the house.

Believe it or not - that is a vast improvement over the first years we got here and didn't have all the leaks on the house sealed (we had to cut down over growth around the foundation to find some of the foundation leaks). I was surprized we got through it so well and were healthier for it. I actually couldn't gain weight while living in 50 to low 60 degrees as a normal daytime temp (nights were closer to high 30s the first years). And you have to give our ancestors credit for thriving under such conditions but I do have to say - it wasn't as un-comfortable as it sounds - you get used to it by getting up and moving around if you are cold or putting on a sweater.

We managed by not heating the whole house - a practice from the Swedes (who built saunas to get warm). After about 6 days of not getting the house up to the 60s, blood thickens and it needs an occational "un-thawing" to get to the extremities again so we had a "sauna" room going once or twice a week, usually on the weekends. Now heating the house to anything over 60 degrees F seems wastefully and hot.

I recommend people try it for a week so they understand what's important to have heat in and how much you can actually go without. Its actually a mind-set.

The other side of this that I found interesting - apparently it was so cool in the house that germs didn't hang out for long on surfaces so we had no instances of colds, flu or other nasty viruses.

That said, the beds are very warm once you get in them. I layered the mattress with a Mylar Reflective material and added a layer into a quit-looking blanket.