The Ratings Game
Problem: Two 20°F bags from different brands may not be equally warm.
Solution: A new standardized system from Europe, called EN13537, that makes ratings consistent. The standard relies on independent labs that test bags using a heated copper mannequin and 20 thermal sensors. REI and Marmot currently use this system, with more companies expected to follow.
Behind the Scenes
Read our in-depth report on EN13537–and learn to decode the ratings–at backpacker.com/ratingsgame.