About half of all working-age Americans experience chronic back pain at some point. For relief, many people turn to heat therapy, a cheap and age-old home remedy.

• 大约所有工作年龄一半的美国人经历过不同程度慢性背部疼痛。作为缓解，许多人求助于热疗，一种古老而廉价的家庭治疗。