Abstract: This invention provides methods for treating cold extremities using localized electromagnetic radiation directed at excitable tissues, including nerves, muscles and blood vessels. By controlling the wavelength, the wavelength bandpass, pulse duration, intensity, pulse frequency, and/or variations of those characteristics over time, and by selecting sites of exposure to electromagnetic radiation, improvements in the function of different tissues and organs can be provided. Responses can be monitored by measuring physiological variables including temperature and blood flow.