Temperature: After the person falls asleep, the head temperature is generally 34-34.5 degrees Celsius, which is a few degrees lower than the body temperature. If the head temperature is too high, it is not easy to fall asleep. Therefore, different latitudes and different seasons, the choice of cold pillows, warm pillows are also very different, the average person often put a mat on the pillow in the summer. So choose the pillow to meet the regional and seasonal characteristics, so that the head maintains the best sleep temperature. Height: Whether you are sleeping on your back or sleeping on the side, it is best to choose a pillow that can maintain the normal curvature of the neck. Adults should be 15 cm high when lying on their back or side. As the saying goes, there is no worry. In fact, the high pillow makes the cervical vertebra too pre-curved, the soft tissue of the neck is over-stressed and fatigued, and it is prone to stiff neck. Over time, it will cause morphological changes in the neck bones, such as physiological bending and straightening. Some people like to sleep without pillows or the pillows are too low, which is not good, will make the head congestion, easy to cause eyelids and facial swelling, and the lower jaw will lift up, easy to open mouth to breathe, snoring. Hardness: The pillow with too hard, the contact area with the head is reduced, the pressure is increased, the scalp will feel uncomfortable, and the pillow is too soft, it is difficult to maintain a certain height, which will lead to excessive fatigue of the neck muscle and affect the smoothness of breathing, which is not conducive to sleep. The pillow is soft and does not lose a certain hardness, in order to reduce the pressure between the scalp and the uneven pressure, so that blood circulation can pass from less pressure. In addition, the shape of the person's head is also related to the initial use of the pillow, the primary child's pillow should be soft and moderate, and pay attention to adjust the head angle from time to time, so as not to grow the head shape is not good. Dc Axial Fan 40X40X15,Industrial Cooling Dc Fan,Laptop Base Dc Fan,Centrifugal Weathering Air Purifier Crown Electronics CO., LTD , https://www.crownelectronicstw.com