Great Cold (da han ??) Seasonal Node.
The Great Cold seasonal node is often true to its name and is the coldest time of winter.
Despite the cold however, the promise of this time of year is the slowly returning Yang. The days are getting longer reminding you that Great Cold is the last seasonal node of Winter. About 2 weeks after the Great Cold seasonal node, both the lunar and solar beginning of Spring arrives.
The three material manifestations of Great Cold are Hens Begin to Breed (Ji Shi Ru ???), Birds of Prey Act Fierce and Swift (Zhi Niao Li Ji ????), and Rivers and Lakes are Frozen Within (Shui Ze Fu Jian ????). Notice here imagery of the impending Spring.
In Five Elements theory the domestic animal associated with Spring is the chicken, and during Great Cold hens are getting ready to become pregnant with baby chicks that will hatch in Spring. Thus, even though the weather outside is still very cold, Yang is definitely on its way back as the gradually lengthening of the days attests to.
As the name suggests, the Great Cold Seasonal Node is the time of the year when the main environmental factor we contend with is cold. The first thing that Chinese medicine recommends for this time is to eat clear and easily digested foods (qing dan shi wu ????).
Why is this? The Spleen and Stomach are the roots of Latter Heaven Qi. During the end of Winter even though the time of the year is still predominantly Yin, the Yang qi is being birthed.
One traditional recommendation for Great Cold is foot soaking and acupressure to support some of the goals we’ve already described above. The time of day associated with Great Cold is the Chou ? hour (1-3am).
While it's not recommended to stay up later than 11:00 PM, this practice can be done before bed, as close to that time as possible while still getting to sleep at a reasonable hour.
Start by soaking feet in hot/warm water for 10-15 minutes, and Epsom salts can also be added to the water if desired. After that follow the soaking with acupressure on Yong Quan KD-1, Tai Bai SP-3 and Tai Yuan LU-9. This helps warm and strengthen the Kidney channel, and supplement the Spleen and Lung channels.
Lastly, gentle massage of the lower back further supports your kidneys. The low back is the abode of the Kidney, and gentle stimulation of the low back can thus relax and warm the Kidney.
Furthermore, Great Cold is specifically associated with the 3rd lumbar vertebra.
There are 24 total vertebrae corresponding one to each of the seasonal nodes, and this association is well known in esoteric Daoist circles.
In the White Cloud temple in Beijing there is a diagram of the body carved in stone on the side of one of the walls that maps out the associations of the vertebrae with the nodes.
So, in light of that correspondence, one great Yang Sheng practice for Great Cold is to sit quietly, starting with vigorously rubbing the palms together to get them as warm as possible. Then, place the hands on the low back in the area, feeling the warmth of the hands penetrating the back. After that rub the back to warm the area, or gently tap the low back.