Knee pain in the cold and no pain in the heat is mainly caused by osteoarthritis of the knee joint, rheumatic joint diseases and other causes. 1. knee osteoarthritis, is due to degenerative changes in articular cartilage caused by a chronic inflammatory changes in the knee joint, due to the destruction of cartilage, in the outside world of cold stimulation leads to local blood circulation slowed down, the blood flow is blocked, resulting in local stress inflammatory reaction caused by the knee joint pain, occurring in the early stage of osteoarthritis of the knee joint. 2. Rheumatic joint diseases, such as rheumatoid arthritis and rheumatoid arthritis, etc. Rheumatoid arthritis generally has a wandering pain, rheumatoid arthritis has the manifestation of morning stiffness, which can be diagnosed through hematological examination combined with physical examination and medical history. These two are inflammatory diseases caused by a decrease in autoimmune function, which leads to abnormal immune changes causing pain when the knee joint is cold. There can be many other reasons why the knee hurts when it is cold and does not hurt when it is hot, so it is recommended to go to the orthopedic department of the hospital for further consultation.