Why a sleeping pad matters The days are getting inevitably shorter, leaves are turning every shade of yellow, orange and red, and the air is turning to that crisp coolness only fall can bring. The warm nights of summer camping will soon be replaced by winter’s icy grip. Although sleeping comfortably in the backcountry during a cold winter night or two takes some practice and knowledge the payoff can be spectacular. Winter has become one of my favorite seasons to get out and camp. It takes more planning, a bit more gear and a bit more knowledge, but the stillness of a winter night and the crackle of a fire in contrast to a deep blanket of snow are hard to beat. In order to help you enjoy your winter camping experience here is important look at what may be the most important piece of gear that can enable you to stay warm all night and enjoy your experience.
Choosing the Right Pad In cold conditions a sleeping pad plays a much larger role than just providing a soft place to sleep for the night, it literally keeps you warm. A sleeping pad acts as an insulating layer between your body and the ground. During a warm summer night that ground generally isn’t too cold, but if you’re sleeping on snow you will definitely notice if you forgo the proper sleeping pad. So how can you know which sleeping pad is right for the job? It’s all about R-Value.
Know your R-Value What the heck is an R-Value you may ask? Well, without getting into the deep definition a physicist would use (because for one reason I’m no physicist) let’s simply say that an R-Value is a measure of thermal resistance, or in simpler terms, a measure of how well an item or object insulates. Sleeping bag manufacturers include an R-Value rating with their sleeping pads in much the same fashion that a sleeping bag gives a temperature rating. In general sleeping pads are rated between an R-Value of 1.0 and 10.0 where 10 provides the greatest ability resists the transfer of heat away from your body and keep you warm. Think of it this way, would you rather insulate your home with just some hardwood siding or fiberglass batting? You likely said the fiberglass batting, but why? Hardwood siding has an R-Value of .91 and 3.5” of fiberglass batting has an R-Value of 10.90.
What about my Sleeping Bag’s Temperature Rating? Sleeping bags are rated in terms of degrees, either in Fahrenheit or Celsius. That is to say if you purchase a sleeping bag rated at 25 degrees Fahrenheit it will keep you warm so long as it doesn’t get colder than that temperature. While that is true there are a number of factors that contribute to that sleeping bag’s ability to do just that. Such things as when you ate last, they type and fit of clothes you are wearing in your sleeping bag, how much room you have in your sleeping bag and so forth. The focus in this article, however, is understanding the importance of the right sleeping pad. A sleeping bag insulates by trapping air, air that is warmed by your body. The “fill” or insulation of your sleeping bag acts in much the same way as the fiberglass batting mentioned above. While we learned that 3.5” of fiberglass batting is a great insulator, what would happen if we compressed that same 3.5” of batting down to .5”? It’s ability to capture and warm air would be completely lost and it’s R-Value would be almost completely lost. The same is true with sleeping bags and the area of your sleeping bag that stays compressed all night long is where your body meets the ground. That means the wherever your body meets the ground your sleeping bag’s temperature rating is being skewed drastically. You’re body weight is compressing the fill and leaving no room for your sleeping bag to catch and warm the air to keep you warm. Instead your body warm is bleeding through the compressed part of your sleeping bag and doing almost nothing to keep you warm. So your sleeping bag may say -25 degrees Fahrenheit and you could still freeze all night long at 30 degrees Fahrenheit if you don’t have the right sleeping pad.
Making the Right Choice There are myriad options when it comes to choosing a sleeping pad. We have talked about R-Value and a pads ability to insulate you, but activity is also a driving force. Car camping and backpacking naturally require different types of sleeping systems so choosing the right sleeping pad for your activity is important. To provide a quick look at sleeping pads and their ability to keep you warm we will compare jut a few most common sleeping pads. Air Mattress: these large and ultra comfortable pads are great for summer car camping. They will provide some great comfort and you’ll likely sleep like a baby all night long, but they are a poor choice for winter camping. Air mattresses are usually 3”-6” thick and hold only air, no insulation. That means you’re body heat has to warm up all the air inside that mattress more efficiently than the ground or outside temperature can cool it. You’ll never win in this case. The air in your air mattress will be cold all night, likely the same temperature as the outside air, which means you’ll be cold. Foam Pad: while foam pads are generally less comfortable and relatively thin, they do provide the most bang for your buck when it comes to R-Value. Foam pads have been around forever and for good reason, they work. Sure they’re not the most comfortable, but they will do well to keep you warm. Keep in mind that not all foam pads provide the same R-Value so be sure to look for a high rating and take into account your intended activity and use (i.e. car camping vs. backpacking). Air Pads: these are smaller and thinner than air mattresses and are more suited for backpacking. Air pads can also provide some awesome insulation as well. However, not all air pads are made with insulation in mind. When it comes to air pads it is very important to look at R-Values as some air pads are made for summer camping while others are made with insulation inside and are better suited for cold weather sleeping. Insulated air pads are among the most comfortable and well insulating pads on the market. They do well to catch and securely hold warm air to keep you warm all night long while still providing you with a comfortable night of sleep.
Wrapping it Up Before hitting the mountains for a cold weather camping trip make sure you’re ready by choosing the right sleeping pad. When shopping for the right sleeping pad look for a higher R-Value. An R-Value around 8 or 9 will keep you much warmer than a sleeping pad with an R-Value of 1 or 2. Remember that a sleeping bag is only as good as the sleeping pad you match with it. With the right sleeping pad you will be ready to enjoy a great night’s sleep even in the coldest of temperatures.