Most of us are guilty of an interesting paradox – we sleep with the air conditioning on yet like to wrap ourselves in blankets or hide under a comforter. Although it seems like a waste of electricity, why are we still inclined to sleep this way?
During the rapid-eye-movement (REM) stages of sleep, one’s brain activity skyrockets, dreaming occurs, and skeletal muscles (besides the diaphragm) are paralyzed to avoid acting out said dreams. In addition, the body’s temperature fluctuates drastically. Due to the increased brain metabolism, a lot of heat is generated which is dissipated by having our heads exposed to the cooler air. We cover the rest of our body to actually retain heat but only to a certain extent. Since we’re not blessed with fins, we find ourselves poking an arm or leg out from under the sheets to also help regulate our temperature. Admit it, you’re guilty of this. 😉
Anyways, to sum things up – too much heat, and you’ll wake up sweating; too little, and you’ll wake up shivering.
On another note, we’ve all had dreams that we can remember and others which we can’t. What determines our ability to recall from the unconscious? Heh, it’s as simple as waking up – you can only remember the dreams that you wake up from since the sleep process is rather amnestic.