Pain when the thigh is cold is usually due to a strain or strain of the muscles in the thigh area, such as the quadriceps or biceps, semitendinosus, semimembranosus, and vastus lateralis muscles, which are not systematically treated or are active because they have not fully recovered, resulting in the formation of local foci of sterile inflammation. These chronic lesions can stimulate the peripheral nerves and cause painful sensations. Under normal circumstances, because local blood circulation is relatively fast, especially in the case of good warmth, it does not lead to vasoconstriction, and the resulting inflammatory metabolites can be metabolized in a timely and effective manner, so there is no painful sensation due to peripheral nerve stimulation. When cold, the blood circulation will be slowed down, the inflammatory metabolites will accumulate, and the peripheral nerves will be stimulated and the pain will be easily felt, and after the cold, the muscle tissue will become more tense and the muscles will not be relaxed and the pain will be easily felt.