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 begin talking about the practical application of r-values by thinking of them as stand alone pieces. The following table lays out recommend 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 depending things like size, weight, packability, durability, and so on. You can play around with these variables for each adventure 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. You don’t want to carry your massive 0 degree 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 for something lighter and rely on the warmer pad and some solid base layers to keep you toasty. If weight isn’t an issue, as with car camping, you have even more room to play.
Things to consider:
As with sleeping bags, these recommendations are based on the mythical “Average Person” and what works for someone else may be a poor fit for you. If you can, rent or borrow sleeping pads from friends or local gear outfitters before investing and see what works for you. The higher the r-value or the lighter the pads get, the pricier they tend to be so a little field research is a wonderful thing.
You can stack pads for cumulative warmth! A popular combination is using a lightweight closed-cell foam pad, like the Therm-A-Rest SOLite under your usual pad. It’s relatively light, relatively inexpensive, and textured enough to prevent slippage when stacked beneath your other pad. With an r-value of 2.8, it’s an easy boost to your sleeping system if you can spare the space for an additional pad.
There you have it, a basic run down! Questions, comments, or concerns? Let me know!