Hope you won't mind some comments on this from someone who works for an outdoor retailer (I'm not trying to flog you any particular product - these are general observations.) You're right about bag temperature ratings not being absolutes, Wes. Two main factors at work here, each of includes a number of sub-variables: 1. Sleepers and their circumstances vary tremendously; metabolism and general fitness level and immediate health vary, as do how well fed, watered, and rested sleepers are (now there's cruel paradox - if you're too tired, you can't get a proper sleep.) Ambient humidity, wind chill, and other local climate effects can make you cold far above a bag's "official" rating. I've had the memorable experience of shivering uncontrollably in a bag rated to minus 10 Celsius during a summer day - however, as I later realised, I was seriously underfed, dehydrated, and tired, plus the air was extremely damp, with a local katabatic wind too slow to be heard, but fast enough to drain heat. The best way to protect yourself here is to know your own metabolism, and to "overbuy" if needed. 2. Unlike say, car gas mileages, there is not a current and compulsory industry standard testing method for sleeping bags. Many of the major players in the US and Canada are currently working to agree on one, which will be based around a US military testing method for CLO ratings - basically a copper dummy wired with thermometers, in a chamber of controlled temperature, moisture, and airflow. Some manufacturers are already using this method as one factor in establishing their ratings. The best bet here is to buy a brand with an established reputation - if they've been around for decades, they must be doing something right. As you noted, manufacturers are tempted to be optimistic with the ratings, and personally, I think a single number is misleading anyway. Although it would be more expensive to test for (and to agree on standards for) I think a range (e.g. "Zero to Minus Ten") encompassing best and worst case scenarios (and bell curved for the statistically inclined) would be the most honest and informative approach. My opinion - worth what you paid for it. Hope it's of some interest. Philip Torrens N49°16' W123°06' > >Buying too much bag not only costs more money, but it is harder to pack >and > >usually less comfortable to sleep in. > > > >Yeah, unless you tend to sleep cold anyway, and/or you believe the bag >ratings, which are pretty optimistic. I have a 20 degree rated bag that's >chilly at 40, for me, anyway. > >-- Wes *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************
This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:33:01 PDT