It is our belief that field testing is the only sure way to know how well a product will perform when it matters. With that mantra in mind, we tested these bags by sleeping in them — outside — a lot. We used them in roasting desert canyons as well as during blizzards at 15,000 feet, and all sorts of conditions and environments in between. Many people slept in each of these sleeping bags, and we enjoyed many pleasant nights out in the wilderness, and more than a few miserable ones to truly understand what is meant by the term: "temperature rating." Our head tester caught two colds that he blames on shivering all night while searching for the truth about these sleeping bags. Suffice it to say that we went the extra mile, and we hope this information is useful for you when making your purchase. Below is a brief synopsis of how we tested and assessed for each of the individual metrics in this review.
For warmth we rated each bag on its absolute warmth, ignoring the manufacturer temperature ratings (which we found were not always very indicative of performance). To do this, we slept in these bags outside in the mountains during the cold spring months of March through June. Springtime in the high mountains of the Colorado Rockies or the Himalayas is not warm, so we came to understand how well these bags worked by suffering in them. Many people have slept in each bag, and we kept notes on where we slept and what the overnight low was and compared them to how we felt and what clothing we wore inside the bags. This information helped paint us a clear picture about warmth, but to attempt to verify our findings objectively, we performed the ice bottle test, where we put an entirely frozen Nalgene water bottle inside each bag and left them laying in the shade on a hot day for an hour. We then made a note of how much the ice had melted during that time to help us fine tune our understanding of which bags were the most insulated. We further amended our opinions by analyzing the function of heat-trapping features(or lack thereof), such as draft tubes, fully enclosed zippers, neck baffles, type of baffle construction, and hoods.
To test and assess for weight was easy. We simply took the new bag out of its packaging and weighed it on our independent scale. In instances with quilts where extra straps are needed to attach the bag to a sleeping pad, or to simply enclose oneself tight inside, we also included the weight of those extra straps. We did not include the weight of the stuff sack in this measurement, although the weight of the stuff sack by itself can be found in the specs table. The lower the weight, the better the score.
When it came to comfort, field testing was once again our bread and butter for determining what worked and what didn't. To ensure objective testing, we had multiple people use each bag, and discuss their opinions afterward. A primary consideration was the fit of a bag, and we ordered all bags to the same size specifications so that we could compare them fairly. We attempted to assess for how loose or restrictive a bag was, how pleasant the interior fabric felt against skin and clothing, and whether features like Velcro, zippers, or draw cords affected the comfort level.
When it came to assessing versatility, we first attempted to identify how many different situations a bag could be appropriately used in, and then did our best to test the bag in all those conditions. Our countless nights out in the field were essential for determining how truly versatile a sleeping bag was. For quilts or blankets that had the option of sleeping wrapped up, attached to a pad, or fully spread out, we slept in them each way.
It is easy to take a new sleeping bag out of the box at home and start to play around with it, but not so apparent is whether the neck cinch cord will really stay tightly cinched around your neck all night when you are cold, or whether the hood truly covers your entire head and forehead comfortably, or whether the pad straps will stay fastened and tight all night, rather than coming loose and allowing in cold air. The only way to truly know these things is to test them in the field, which is what we did, over and over again.