Thermal modalities are by far the most commonly used modality in the rehabilitation setting. They have been used for decades to provide complimentary treatment to a host of maladies. This course provides a review of the purpose and physiologic basis of the application of thermal modalities as well as the indications for and contraindications to their use. In addition, it provides a review of the available evidence about their safety, efficacy, and clinical utilization. The course covers such modalities as ultrasound, phonophoresis, diathermy, low level laser therapy, fluidotherapy, and paraffin. It also covers more readily accessible modalities such as hot packs, ice, contrast baths, and whirlpool. It is anticipated that the student will have a thorough understanding of the scientific rationale for using various types of thermal modalities and which modality is most appropriate for a given patient condition.