Sleeping Physical Body

The air surrounding the sleeping physical body should be as fresh as ever but if one lives in a cold climate, that air may be a mixture of cold air from outdoors with hot air heated indoors. One can have a slight opening where cold or very cold fresh air enters. To be in an air tight room except for air vents for heated or cooled air is insufficient, unless that air is fresh air.

In most houses the return air vent pulls air from within the building. This means that it heats or cools a mixture of carbon dioxide and fresh air but the fresh air enters the building only if window (s) is open and only when the exterior door(s) is open. If a yogi sleeps in a building where there is no opening to accommodate outside air, he/she will be breathing a mixture of fresh air and stale air in varying proportions.

Eventually the air will all be stale air, especially if it is a small room.

Why bother with the condition of the air, as to if it is fresh air or stale air, consisting of mostly oxygen or mostly carbon dioxide?

A yogi should be concerned about this because if the physical body has to use carbon dioxide (stale air), then there will be a lowering of the frequency of the subtle body, such that it will go to lower astral regions when it is separated from the sleeping physical body. This will result in bad dreams, nightmares, encounters with disagreeable people and the like. This may cause sleep paralysis which is the condition where when the subtle body should resynchronize with the physical system, it is unable to do so, and the effort to wake up as the physical body, results in frustration where one cannot move the limbs of the physical body to act as that body on the physical side.

This happens frequently when there is no continuous access to fresh air. The kundalini in the physical body is unable to transmit the best energy to energize the subtle form. By all means a yogi should be in a fresh air environment, especially when sleeping.