I bought a few of these for me and my boys about a hundred years ago. It was back before really good, warm, hunting clothing was the norm. It was also before I could afford stuff like Browning's Hydrofleece.

They are fairly warm and comfortable and you can unzip it at hip level, stick your feet out and walk normally while the top half wears like a jacket. The bottom half ties around your waist and you can sit on it to stay dry or as extra padding.

Swedish military sleeping bag.