Originally Posted by
Coldhands
Hey all,
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On the GDMTR they recommend a 20/-7c bag, however I'm starting late in the season and my bag is valued at 0c. I could buy something like a -12c bag to be on the safe side, but then I'm going to be going on to Mexico and then Cuba, so I had an idea of keeping my 0c bag, which is fairly flexible, but buying a down quilt. This way I can keep the quilt as a backup, and then once I'm further south mail either the bag or the quilt home. I'm also intending on taking a high-end goosedown gilet and some thermals. Would this setup be suffice for camping out in fall along the GTMBR? If the quilt is rated to say 4c, and the bag 0c, is there any way to predict what temperature they would be good against when used together? Any other suggestions or thoughts are welcome!
Many thanks,
Coldhands
The general rule of thumb I use for combining bags is (Rating of the heavier bag)- (55 degrees-temperature rating of the lighter bag)
It's just a guideline, and things like drafts and loft compression also factor in, and the added fiddle factor of combining multiple bags.
Don't forget, you can usually add another 5 or 10 degrees to the value of your sleeping bag by using an enclosed tent (or bivy) and maybe another 5 or 10 by sleeping in all your clothes. Your down jacket is going to be key to this. Some people are happy to do it all the time, but I try to keep that option for unexpected extremes.