The winter season is the sleep of nature. Days are short and nights are long. Humans long ago stopped hibernating like their ancestral cousins, but our bodies still experience the slowing of natural processes in winter. According to Chinese medicine, the winter season is linked to the kidneys, the adrenal glands and the bladder. Toxins and carbon dioxide tend to accumulate due to inactivity; people are prone to colds, flu, poor circulation, and low vitality. Says the Yellow Emperor: sleep early and wait when you can, to let the sun bathe the house before rising from bed, dress warmly and engage in physical exercise, refrain from the cold and raw foods in your diet, reduce salt to protect the kidneys but increase bitter flavors, be happy, and prevent the stirring of emotions as much as possible. These are the ways to avoid the winter blues.