My low-tech keep-warm solution this past winter was the mighty hot water bottle. It cost $5 from some knick-knack store and it does an excellent job of keeping

My low-tech keep-warm solution this past winter was the mighty hot water bottle. It cost $5 from some knick-knack store and it does an excellent job of keeping my sheets warm until long after I've fallen asleep. It saved me from shelling out for an electric blanket.