As the body’s metabolism works throughout the night, perspiration is released as water vapor also called insensible perspiration. Synthetic fabrics trap and hold this moisture because air can’t circulate. As body heat and moisture build up, your heart rate increases, which elevates blood pressure and causes shallower sleep. At a time when you should be resting, your heart isn’t. You may awaken in a sweat, unable to return to sleep, or you may wake up in the morning feeling like you didn’t get enough sleep. You didn’t; you lacked the deeper delta sleep cycle that contributes to good health.
Breathability and Temperature Regulation of Bedding Materials
Wool filled bags allow the body vapor to pass unhampered which has the effect of feeling more like there is no cover around you even though you are warm and protected. It is a unique experience in sleeping that few people have had. That is…to be in cold air and yet not feel like you have covers. The wool fabric and fill actually wick moisture away from the body which is the opposite of the other two types of bags. The combination of factors have a synergistic and calming effect on the body.
Also the metals in the synthetic material actually short out the electrical flow in our body (synthetics come from petroleum). That means the body cannot ground. This is demonstrated in the static electricity that builds up on synthetic fabrics which anyone can easily see….those sparks that fly off of it. That same static electricity builds up in the body when exposed to external sources of static.
Science is showing that – as well as being a natural, renewable and biodegradable fiber – wool bedding and sleep wear appear to promote a better night’s sleep, and fine wool knit wear can assist people who suffer from particular types of skin conditions.
Consistent with earlier science findings, the early results from a study undertaken by the University of Sydney, Australia, are showing that wool sleeping apparel and bedding increases total sleep time, promotes sleep onset and improves sleep efficiency.
And another recent study reveals yet another even more astounding property of wool. A scientifically measured super frequency that elevates the human body’s own frequency from 100 to 5000. Click here for The Linen (and Wool) Study.
In hot (29° Celsius) conditions, wearing wool sleep wear saw participants in the study sleep significantly longer, reflecting faster sleep onset and waking up less frequently. In both cold (17° Celsius) and neutral (22° Celsius) conditions, the combination of wool sleep wear and bedding saw participants have a more efficient sleep compared to when tested using non-wool sleep wear and bedding.”Source.
The body actually becomes adapted to the cold with exposure to the cold. Part of this process is hampered by synthetics because of the lack of breathability and the interruption of the electrical current along the skin (Peizo Electricity).
And this cold adaptation, if it is allowed to take place, has dramatic health enhancing aspects in itself.
This sleeping bag allows the body to function the way it is designed to and thus go through the natural process of becoming cold adapted because part of that process is allowing the natural ability of the skin to breathe.
Also the body temperature and moisture exchange is regulated in a way that one wakes up feeling almost as if there is no covering even when in sub zero temperatures. You wake up and feel like you are in the perfect temperature of air, when it is frozen within inches of your skin.
Following is an excerpt from another sleep study with link to source:
There are few practical studies on the effect of fabric type for bedding, on sleep. A study found that sleeping on woolen underlay significantly lowered body movement, reported higher subjective sleep quality, and better feeling in the morning when compared to the control pads.16 A study that compared wool-filled duvets and polyester-filled duvets at 16°C revealed that heart rate and the microclimate temperature and humidity were lower for wool during the sleep period.17 Lower sweat production, Tsk, and microclimate temperature and humidity were observed with wool blanket compared to acrylic–fiber–cotton blends under warm and humid conditions.18 The authors ascribed these changes to the moisture-buffering and transport properties of wool fibers.18 However, none of these previous studies recorded objective sleep measures using polysomnography (PSG). http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4853167/