When people think of camping, they often think of their childhood adventures, perhaps sleeping in the back yard. Often your “gear” was simply a sleeping bag on the ground. Many times your outdoor escapades ended with you heading to your bedroom and its nice, warm bed. Remember getting chilled sometime before dawn? Well, the main reason you got chilled is because you probably didn’t have an insulating pad under your sleeping bag.
Contrary to what most people believe, a sleeping pad isn’t just for softening the earth beneath you; it’s to provide insulation against the cold of the ground. Even in summertime, the ground is cooler than the air temperature. As you can read in the section on Sleeping Bags, insulation is provided by loft. While in a sleeping bag, the loft is compressed beneath you. This puts your body almost directly against the ground, where the coolness transfers itself to you. The purpose of the sleeping pad is to provide that insulation. There are several options available to you which are described below.
- Closed-cell foam pad. Dense foam that provides good insulation but not much cushioning. This is a good choice for lightweight, durable, and inexpensive insulation. The standard flat pads do not provide much cushioning, but some makers have improved on the design by adding ridges that allow more softness and give. One of the most comfortable of these is the Cascade Designs’ Ridge-Rest. Even though these pads are lightweight, they are bulky and difficult to strap on a pack where they won’t get beaten up.
- Self-inflating air mattresses. Not to be confused with the air mattresses that you take to the pool. The pad is made up of a foam core bonded to a waterproof shell that expands upon opening a valve on the corner. Cascade Designs introduced this with their Therm-a-rest Air Mattress and continues to make some of the best. Others in this class are the Nemo Astro Inflatable Pad and Big Agnes Air Core Pad Mummy. These pads not only provide insulation against the coldest ground, but they are comfortable as well. I can’t imagine taking any trips without an inflatable pad. They tend to be heavier than the basic closed-cell foam pad, but the good nights’ sleep I get from them more than makes up for the extra weight. These pads are expensive but worth it! The newest designs weigh less, but this lightness comes at a cost of being more delicate. If you take care of them, they will give you many years of comfort and enjoyment. To help your mattress last as long as possible, store it flat with the valve open. This allows any moisture inside the foam to dry out and prevents the foam from breaking down. To minimize the amount of moisture that gets inside, allow the pad to self-inflate as much by itself as possible. Then blow any additional air into it to get it to the firmness you desire.
- Open-cell foam. This is the foam used in egg-crate mattress pads and it is basically worthless for backpacking. It compresses too much to provide good insulation, and it’s extremely bulky as well. Some companies have come up with a combination foam pad by incorporating closed-cell foam bonded to open-cell foam. This provides more comfort and insulation, but the bulky size is definitely a disadvantage.
- Air mattresses. Keep these at home on a nice carpet or for use in the pool. They are so vulnerable to punctures that you are taking chances using them in the backcountry, especially in the rocky, thorny southwestern deserts.