I recently did an article on selecting sleeping systems for SHTF. Having a quality sleeping bag is a necessity in most climates, but it is only part of the story. Insulating yourself from frozen ground, ground moisture and wind are also critically important.
Without trying to get into the science of thermodynamics, suffice to say that if you lay your warm body on the cold ground, the ground will win the contest. It is a mass that you will never reach equilibrium with, so it will pull heat energy from your body until you are the same temperature as it is. So you need insulation between you and the ground. Since the insulation in your sleeping bag will be compressed underneath you reducing it’s effectiveness, the sleeping pad is an essential piece of gear in your sleep system.
The R Value
Insulation is measured according to its capacity to resist heat flow. That is called an R value. The R-values are provided by the manufacturers and range from 1.0 (minimally insulated) to 9.5 (well insulated). Thicker pads generally offer higher R-values but are heavier.
Types of Sleeping Pads
Inflatable Air Mattress: Although they provide a lot of comfort compared to sleeping on the hard ground, I feel they have some drawbacks for SHTF survival. For one thing, with hard usage they will leak. I don’t care how well made they are. I used them in the Army (fondly refered to as the Rubber Lady), and without air, they are useless for insulation. If you are bugging out by vehicle, they may have some merit as you can easily inflate them from your vehicle accessory plug using an electric pump. But you really need to have a pad that you can carry with your sleeping bag in your bug out bag for bugging out on foot.
Closed Foam: These are basic pads and are usually lightweight with good insulating qualities. Therma Rest is a company that make an excellent line of sleeping pads. The Therm-a-Rest Z Lite Mattress is a good example. The foam construction is soft on top and dense on bottom. It has an R value of 2.2, weighs 10oz.
Self Inflating: These are foam mattresses that will self inflate to some degree. They offer a combination of additional comfort as well as good insulation: The Therm-a-Rest Trail Pro Mattress is an example. It has an R value of 4.0. It weighs in at 2.7 pounds.
These are just a few examples of the types of sleeping pads you should consider for your survival sleeping system. The idea is to get insulation between you and the ground to retain body warmth in a package that you can travel with.
As always, decide what you need, do your research, and buy the best quality you can afford.
3 thoughts on “Ground Insulation When Sleeping Outdoors”
Nicee blog thanks for posting
Please check your numbers. 51″ would be too short for an adult, and 15x7x7 would be a small pillow.
Thanks for catching the typo