Thermal stimulation of the joint increases blood flow around articular cartilage, promotes diffusion of nutrients to the cartilage and metabolic wastes from the extracellular space. The exposure of a joint to proper elevated temperature is important because it also boosts production of heat shock protein HSP70 which protects chondrocytes from apoptosis and induces multifold increase in chondrocytes metabolism. As a consequence, it synergistically intensifies the biochemical processes triggered by PEMF and directed to the cartilage healing. Mediated by HSP70, the DNA transcription in chondrocytes accelerates by 4 to 7 times and produces significantly more proteoglycans and collagen II than it would be possible at normal temperature. In addition, thermal stimulation alleviates pain, relaxes surrounding muscles and makes the treatment comfortable.