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A mattress will smooth the way for old bones and warm your backside when you sleep on cold ground. There are four basic types of mattresses.
Air Mattress
Except for car camping, the traditional air mattress is extinct. Except in the heat of summer, air mattresses cannot be used with down sleeping bags. Body weight compresses an air mattress down to near-zero thickness: if the ground is cold, your backside is too! If you want to be comfortable and warm, place a thin, closed cell foam pad on top of your air mattress.
Closed Cell Foam
Closed-cell foam insulates efficiently and is waterproof, inexpensive, and unaffected by punctures…and not very comfortable. It’s the foam of choice for subzero camping, however, where a mattress failure could be serious. Three-eighths of an inch is thick enough for summer: double that for use on snow. It is the best pad for children, especially those who may wet their beds.
Fabric-Covered Open Cell Foam
A trail mattress of this type is basically a huge sponge covered with nylon or cotton. This design is reasonably comfortable, inexpensive, unaffected by punctures, and not waterproof. Open-cell foam is bulky when rolled, and it doesn’t insulate as well as closed-cell-foam.
Air-filled Foam Pads
The Therma-Rest began the revolution; now there’s lot of competition. Basically, these units consist of a low density (think soft and cushy) open cell foam that’s sealed in an envelope of vinyl and nylon. An over sized plastic valve controls the air flow. Open the valve and the pad inflates itself. Close the valve to lock in the air. The result is a very comfortable, incredibly warm (suitable for subzero use) and surprisingly reliable mattress.
