Why did the ancients use wooden pillows? What are the benefits?

Ancient people are said to have used rosewood as pillow fabric, filled with a variety of beneficial herbs. Later there are sandalwood, cypress, incense wood and other wooden pillows, as well as stone pillows, jade pillows, etc., which are hard pillows. We usually choose the pillow, soft and hard to moderate, if the pillow is too hard, will feel the head, scalp pressure, local pressure pain and pressure numbness, had to roll over, so it will prevent sleep. On the contrary, if the pillow is too soft, the head into the pillow; side sleep, so that the breath change feel bad, also not conducive to sleep. Generally speaking, soft pillow is warm, hard pillow is cool. In addition to the hot summer in the north, generally do not use a hard pillow; and the south due to the long hot and humid time, sleep soft pillow will feel sweaty pillow hot, uncomfortable head. If the pillow hard pillow sleep, due to better heat dissipation, so that the head is cool, beneficial to sleep.