 The investigators targeted the patients with chronic LBP. After treatment in 2 groups - real heating and cooling combination treatment and sham heating and cooling combination treatment - the investigators will compare the effects of pain relief and improvement in disability and range of motion of lumbar region. So the investigators will confirm the efficacy of heating and cooling combination therapy, and further the best treatment method. In addition, the investigators are going to evaluate the safety of abnormal reaction during the treatment. 