Heat Therapy: Targeting Health, Disease, and Disability.

Heat therapy is a historic modality that has been used as a source of lifestyle intervention and community for many different cultures. Over the last ~40 years, heat therapy has gained increasing popularity among scientists and clinicians as a potential therapeutic tool for aging and disease. Recently, several systematic reviews and meta-analyses have sought to encompass specific aspects investigated in the scientific literature surrounding this ancient therapeutic modality, with each review having a primary focus on one beneficial aspect of heat therapy. This review aimed to provide a more comprehensive review of the scientific literature on heat therapy. To accomplish this, we have included studies that demonstrate clear beneficial adaptations (and those that show no effect of heat therapy) on specific organs, crosstalk between different organs and tissues, and integrated physiological systems and pathways. Furthermore, we also discuss what forms of heat therapy confer beneficial adaptations and for which populations these benefits occur. Where possible, we identify specific signaling mechanisms through which heating a tissue or raising internal body temperature results in a multitude of beneficial adaptations. Lastly, this review also emphasizes those investigations that have shown little or no benefit of heat therapy. The overarching aim of this review was to provide scientists, clinicians, and the lay public with a current consensus on the benefits and limitations of heat therapy as a healthy lifestyle intervention for a variety of persons and health conditions.