One of the more important pieces of gear in your backpack should be your sleeping pad. Although proper clothing, a sleeping bag and shelter are all important to your enjoyment of the wilderness, your sleeping pad is your first defense against creeping cold air. A good sleeping pad will use your body's heat to insulate your sleeping body in the backcountry. Choosing a sleeping pad is relatively simple, but you must make several personal preference decisions.
Decide how long your trip will be. Thick, bulkier sleeping pads provide better insulation and help you sleep warmer, but if you're trekking 20 or more miles a day for a long period, you'll want to consider a lightweight model.
Decide between foam and inflatable pads. Foam pads--especially closed-cell pads--insulate better than inflatable pads, but can be difficult to pack each morning. Inflatable pads offer better comfort for your body, but be sure to get an insulated one--the noninsulated ones simply trap cold air.
Decide whether lightweight is for you. For example, a lightweight, open-cell foam pad (which is 70 percent less effective than a closed-cell pad) is about the least amount of weight you could carry. At the same time, you'll be sacrificing both comfort and insulation.
Choose a heavier option if you have problems sleeping. Either a closed-cell foam pad or insulated inflatable model give you a warmer sleeping situation and more comfort for your back. You will, however, be carrying more weight and bulk than if you choose a lightweight model.
Understand that inflatable models are likely to puncture. Although it's not too difficult to repair punctures in the backcountry--though you may need to immerse the pad in water--it can be frustrating. When laying out an inflatable sleeping pad, make sure the ground is free from rocks and other debris.
