Now that we have chatted about sleeping bag ratings, it’s time to hit on the next piece in the comfort quiver: your sleeping pad!
Whereas sleeping bags are given an EN/ISO rating, sleeping pads get an r value that indicates their thermal resistance. The higher the number, the warmer the pad will keep you! It’s important to note that unlike the EN/ISO rating, there isn’t (yet!) a standardized testing procedure for assigning r-values. Some brands conduct rigorous internal testing, others simply guesstimate based on the available data. Do your own research on the brand before taking the rating they give their product at face value.
Let’s being talking about the practical application of r-values by thinking of them as stand alone pieces. The following table lays out estimated r-values for different climates:
This is a helpful starting point for thinking about climate, warmth, and what sleeping pad you want to bring with you. Now, let’s think of your sleeping pad as part of a sleeping system that’s comprised of your pad, your sleeping bag, and the clothes you are wearing. Each part of the system has a different temperature rating, with pros and cons pending things like size, weight, packability, durability, and so on. You can play around with the variables to balance things out. For example: let’s say you’re on a fall alpine adventure and the temps are expected to drop into the frigid zone. You don’t want to carry your massive sleeping bag and you have an ultralight sleeping pad with an r value of 5.7. In this situation, you can likely forego the heavier bag and rely on the warmer pad and some solid base layers to keep you toasty. Ultimately, personal comfort will vary and testing of the variables is important so keep all of these things in mind as you shop, pack, and play!
Questions, comments, or concerns? Let me know!