Summer is approaching, air conditioning and electric fans will return to our lives, but we enjoy modern tools with abandon, but also please do not forget that they are on the human joints, especially the knee joint “toxic side effects”. Osteoarthritis (OA) is a common disease of the elderly, but now there are many patients less than 40 years old have begun to disease, the clinic has even been able to s to more than 20 years of age OA patients, the disease is the most important symptom is the disability caused by pain in the joints, will seriously affect the survival of patients and quality of life, the hip and knee joints are the most commonly affected by the disease parts. When air conditioners and fans bring us coolness, the exposed knee joint is often the first to suffer, especially for young women in revealing clothes. To make matters worse, because of the widespread use of air conditioning, people move from one place to another, in effect from one air-conditioned area to another, so that our precious bodies frequently “enjoy” high and low external temperatures; many people are also accustomed to sleeping with the air conditioning on all night. In this way, the vulnerable knee joint is constantly exposed to this so-called “coolness”, which gradually becomes an important factor in the development of osteoarthritis over time. On the other hand, in many patients with clearly diagnosed OA, they follow the advice of their doctors and pay great attention to the warmth of the knee while actively treating it, achieving good results. Usually, we advise patients not to expose their knee joints directly in an air-conditioned environment, avoid air conditioning and electric fans blowing directly on the knee joints, try not to wear skirts and shorts, but to wear thicker fabric pants, and preferably also use thin warm knee pads for summer. As the ancients used to say, “prevention is better than cure,” the same prevention of osteoarthritis, the heat of the summer, still pay attention to the knee warmth, do not let the knee catch a cold. For patients who have been diagnosed with OA, it is even more important to keep the knee warm in the summer, which is an extremely important part of the overall treatment plan.