Ten patients with Raynaud's disease treated themselves at home using induced vasodilation 3 times/day, every other day, for 18 treatment days. The patients, dressed in indoor clothing, immersed both hands in warm tap water (43-45 degrees C) for 8-10 min while exposed to naturally occurring ambient cold. Results of pre- and posttreatment cold exposures showed a significant mean increase in digital temperature of 3.4 degrees C (p less than .001). Conditioning therapy appears to be an effective, feasible alternative to drug or surgical therapy.