In camping, a ground pad, sleeping pad, sleeping mat, roll mat, or iso mat is a simple device often used in conjunction with a sleeping bag. Its purpose is to provide padding and thermal insulation. All types currently available use air as their primary form of insulation. Closely related to the air mattress a pad of this type requires an external pressure source to inflate, typically in the form of a pump or by blowing orally.[1] Convection of the air inside the mattress reduces the amount of insulation it provides and more complicated mattresses include methods to reduce this by either partitioning the internal cavities, or by filling the cavities with material to trap the air such as down feathers or synthetic insulation. An example of a 183x51x3.8 cm self-inflating mattress, made from diamond ripstop. The black high volume valve can be seen in the left foreground. An extension on the conventional manually inflated mattress, this type is capable of self-inflation due to the open-cell foam that fills the internal cavity.
For many years this design was protected by various patents held by Cascade Designs[2] and they were an unusual and premium item. But since these patents expired many other manufacturers are now producing this type of mattress and they are now commonplace. These mattresses are lightweight and pack to a small size, which make them popular amongst hikers and campers. A self-inflating mat typically measures 183x51x3.8 cm, weighs about 700 g, and packs to about 28x16 cm.[] Closed-cell foam is used to produce mats that can be used without requiring any inflation. Closed-cell foam pads are lighter and more durable than their air-filled counterparts, as they are constructed of fewer materials. Many may also be trimmed to size should the user choose to do so. However, they are generally not as comfortable as air-filled mats because they are thinner, and may also take up more space in a pack, depending on the materials used. Variations include textured or shaped foam to increase the unrolled volume and/or change the stiffness of the mattress.
This can also be used to trap the air within ridges or an egg-carton type of texture. Related to Sleep Disorders Memory Foam: Pros and Cons Considering a memory foam mattress or similar product? Read what sleep experts say about it. Few things feel as good as a good night's sleep. That's especially true if sleep seems to escape you, night after night after night. If you've heard about memory foam, you may wonder if it could improve the quality of yoursleep. Some people swear by it. Others are less enthusiastic. What exactly is memory foam? And what are its pros and cons? Here's information to help you decide whether memory foam is worth a try. What Is Memory Foam? First designed in the mid-1960s for NASA airplane seats, memory foam is made from a substance called viscoelastic. It is both highly energy absorbent and soft. Memory foam molds to the body in response to heat and pressure, evenly distributing body weight. It then returns to its original shape once you remove the pressure.
In addition to protecting against impact, these properties make memory foam very comfortable. After its "virgin flight" for NASA, memory foam made a foray into other applications. For example, it was used as cushioning in helmets and shoes. Medicine found a use for it in prosthetics and products to prevent pressure ulcers such as seating pads for people who are severely disabled. Then, memory foam really took off. It's now well known for its use in pillows, mattress pads, and mattresses, which come in different densities and depths. What Are the Benefits of Memory Foam? Could the special properties of memory foam enhance your sleep? Sleep specialist Donna L. Arand, PhD, says that objective studies supporting the claimed benefits of memory foam -- or the effects of any particular type of sleeping surface -- are lacking. This is true for a variety of reasons, she says. This type of sleep study can be expensive, if conducted independently. Or it is "chased" by a shadow of bias, if supported by industry.
Also, some sleep technology, such as memory foam, is relatively new, so it hasn't been well studied. But perhaps one of the more difficult stumbling blocks to testing the health benefits of mattresses such as memory foam is the subjective nature of sleep. It is simply difficult to measure. Sometimes the brain's electrical activity, measured with an electroencephalogram (EEG), and other findings recorded during a sleep test don't always match up perfectly with a person's subjective experience, says Arand, who is the clinical director of the Kettering Sleep Disorders Center in Dayton, Ohio. "They might say, ‘I had a great night's sleep,' but the EEG parameters might not really indicate that." Sleep is not only subjective, but preferences for sleep surfaces are individual, Arand says. "There's quite a bit of variability between individuals in terms of what type of surface -- whether it's firm, hard, or soft -- they prefer when they're sleeping," she says. "As far as we know, there is no rhyme or reason for that."
Many of Arand's patients who use memory foam have offered unsolicited glowing reports like these about memory foam: "I'm sleeping great." "Best sleep I've ever had." "I love going to bed at night." Arand says these anecdotal responses may be one-sided. That's because she and other staff don't ask all their patients about their sleep surfaces. "We may only be hearing the good stuff," Arand says. Kathy R. Gromer, MD, sleep specialist with the Minnesota Sleep Institute in Minneapolis, agrees that memory foam may improve sleep. "It can, if it relieves painful pressure points," she says. But Gromer adds that memory foam doesn't do anything for sleep apnea or other sleep-breathing disorders -- and sleep disorders are the primary complaint of most her patients. "When you lie on the memory foam, the heat from your body softens it in appropriate points," Arand says, "so this helps to support your body along the curves and natural lines of the body." Memory foam manufacturers claim this helps relieve pain and thereby promotes more restful sleep.
And, though consumers often believe that very firm mattresses are best, more "giving" mattresses like these may lead to better sleep in people with back pain, according to the National Sleep Foundation. Although there aren't scientific data to support the hypothesis, Arand wonders whether memory foam sleep surfaces might be especially helpful for older people. For them, minimizing extra movement could reduce the number of times they awaken during the night. Being less aware of a bed partner's movements might be an extra benefit, she adds. "Without the coiled springs, you feel your sleep partner's movement less, and that might help, too." What Are the Disadvantages of Memory Foam? Gromer says that memory foam products may retain body heat, which could make them less comfortable in warm weather. However, Arand has not heard this complaint from her patients. "In our culture, most people can adjust their thermostats or blankets for the appropriate season," Arand says. When new, memory foam can produce an odd chemical smell -- a phenomenon called offgassing.