In 1989, we developed a form of thermal therapy for heart failure. In 2007, I changed the name to Waon therapy: “Wa” means soothing, and “On” means warmth, hence Waon infers soothing warmth that comfortably refreshes the mind and body.   “Waon therapy” is defined as “therapy in which the entire body is warmed in an evenly maintained in a far infrared dry sauna at a temperature of 60°C for 15 min, and then rest supine on a bed outside the sauna where they are covered with blankets for an additional 30 min, with fluids corresponding to perspiration being supplied at the end.”   Waon therapy has several characteristic features, that is, safe and no toxicity, gentle and cost effective. It is just a holistic medical care and gives a global optimization to the patients with refractory diseases.   There are various clinical applications of “Waon therapy and the effects are often dramatic. In particular, a drastic recovery is often seen in severe congestive heart failure (CHF) as well as peripheral artery disease (PAD) with intractable ulcer, chronic fatigue syndrome, fibromyalgia syndrome and salivary secretion failure caused by Sjögren’s syndrome etc. In this presentation, I would like to focus the effects and mechanisms of Waon therapy on refractory CHF and PAD.   We demonstrated that Waon therapy improved the hemodynamics, cardiac function, ventricular arrhythmias, vascular endothelial function, neurohumoral factors, sympathetic and para-sympathetic nervous system function, and also found that 2 - 4 weeks of Waon therapy (once a day, 5 days a week) significantly improved clinical symptoms, and deceased BNP and cardiac size in patients with CHF. Waon therapy improved the prognosis of CHF patients as well as CHF models of hamster and mouse. It has also been demonstrated that the molecular mechanism by which Waon therapy improves vascular flow and expression of endothelial nitric oxide synthase (eNOS) and capillary density.   Moreover, repeated Waon therapy is effective for patients with severe PAD, as evidenced by substantial decrease in pain scores, increases in both ankle-brachial pressure index and blood flow assessed by laser Doppler perfusion imaging, and by formation of new collateral vessels on angiography. Waon therapy often heals ischemic ulcers markedly. Waon therapy upregulates heat shock protein 90 (Hsp90) and leads to angiogenesis through the akt-eNOs pathway in mouse hindlimb ischemia.   In conclusion, Waon therapy is an innovative and highly promising strategy for cardiovascular diseases, especially treating refractory CHF and PAD.