Coldness in both thighs may be caused by environmental factors, thrombosis of the lower limbs, and lumbar disc herniation. 1. Environmental factors: Due to the low temperature of the environment, and wearing less clothes, the phenomenon of cold thighs may occur. It can be relieved by increasing or decreasing clothing and adjusting the room temperature. 2. Lower extremity thrombosis: Lack of exercise and poor blood circulation in the lower extremities can lead to the formation of lower extremity thrombosis. It will make the local blood circulation is not good, resulting in insufficient blood supply to the legs, the temperature is lowered, may appear double thighs cold situation. 3. Herniated lumbar disc: As the herniated lumbar disc compresses the spinal cord and nerves, it causes ischemia and edema of the nerves, which may lead to abnormal sensation in the legs and the symptom of coldness in both thighs. If the coldness in both thighs cannot be relieved even after eliminating environmental factors, you should go to the hospital in time and ask the doctor to make a clear diagnosis and treatment.