The rating system is not very honest. They are factoring in appropriate clothing, not a hypothetical nude user. Individual metabolism is highly variable. Some people "sleep warm" while others do not. The pad is critical. I spent a sleepless night in an "Arctic"rated -15 bag, in the desert. I had only a groundcloth. The down fill was useless compressed. The next night I used sweaty horse blankets. I was warm, but smelly.The third night I made a bed of dried cowpies.

ewwwwwww<br><br>I think I'd rather stick with the horse blankets.

The rating system also varies from one manufacturer to another, and it is highly informal. I am surprised that a bag that didn't close around the shoulder (basically a mummy configuration) could be "rated" to 0 degrees. Heat loss from the neck and head is critical at even moderately cool temps. And there are many personal variables, including the amount and type of food you ate before retiring., wind, etc. etc.

Regardless of ratings, my regular sleeping bag is comfortable down to around 40F. Are there liners or other means by which I can make it comfortable down to 20F?

You might want to try one of the fleece liners in your bag to bring down the rating. They also work well in moderate weather as a light sleeping bag.

Willie,<br><br>My first suggestion is get another bag... there are some very roomy bags with hoods available these days.<br><br>I'm guessing that the main problem with your rectangular bag is the drafts at the top. Does it have a drawstring? If not:<br><br>If your shoulders are not too close to the top of your bag, rig up a way to close it up around your neck. It would be fairly simply to sew on a drawstring tube for a "permanent" fix.<br><br>Poncho liners, blankets, and fleece blankets work well. Fleece blankets inside a nylon bag are nice and as a bonus, the static electricity discharges are impressive! (I worry about the boys in those sometimes - farts + ignition sparks =... just kidding!)<br><br>All the above seem to be too short for average and taller men, so what I do is use the poncho liner/blanket diagonally inside a bag, 80% over me and a little tucked here and there under me to chink up drafts. Tuck your feet into one corner (wrapped under so you can trap it) anduse the rest over you and to chink up the holes at the top of your bag. Even a thin blanket inside adds a lot to most bags comfort rating. Don't add too bulky a blanket or you'll get cold spots from compressing the insulation on the sides/top.<br><br>If you have a full-length parka of proper (loose) size, unzip it and spread it out under the bag so that it's where it would be if you were wearing it inside the bag. Climb in, then zip up the parka (minus arms) and cinch down your hood. Uh - it's like... imagine you are wearing your sleeping bag inside your parka, but without your arms in the sleeves. That works really well (a plug here for the M1951 surplus parka, which does this job handily). If you coat does not have a hood it's not as good, but still works. It's really hard to make it work well enough to last thru the night if your coat is short - it tends to ride up off you, but the cool breeze helps remind you to re-adjust things <grin>. No way will it work if your parka is fashionably tight, tho. In that case, you can try wearing the parka inside the sleeping bag, but... it's usually confining, I do not like outerwear in my bag if I can avoid it, and it usually does not work well unless the bag and parka are designed for each other.<br><br>You CAN use a vapor barrier, and they work in a hooded bag. I made one out of coated ripstop nylon many years ago and used it if I absolutlely had to. I do not like them, but freely admit they work. My circumstance was different - high quality down bag ( I NEEDED the space and weight reduction) on extended winter trips in interior Alaska. Mostly I was paranoid about condensation inside the bag - I often could not make the choice to not perspire some, and drying off before getting in the bag was NOT an option most of the time. And taking time out to dry out my bag was not an option, either. It did the job.<br><br>I still have the VB bag I made - very simple, and it has a drawstring -sorta like an elongated, durable garbage bag. I frequently have it in my daypack in certain locales as part of my "emergency" stuff, and have loaned it to one or another son on various trips when they were otherwise sleeping a little cold. Like I said, it works in a hooded bag. Gets moist inside, and the coating is not nice to touch. Adding a poncho liner inside works to reduce those sensations. Getting out of it at the end of the sleep period is brisk! The moisture flees quickly... the stench seems to linger longer.<br><br>Hope this helps<br><br>Tom