How neurofeedback treatment is administered depends on the practitioner. There is no government licensing or certification in the field. Many types of equipment are used. The experience and skill of the practitioner seem to add value though. This field should be distinguished from biofeedback.
Cold hands can be one sign of stress.
By learning to induce more relaxed states, many patients improve from various psychological ailments that involve excess stress. Each one seems to require a different application of neurofeedback, and is specialized in by different practitioners. One of the encouraging things about the book is a complete list of research reports, descriptions of which practitioners treat which areas, and ways to get more information from web sites and manufacturers. The author also tried neurofeedback and reports his positive and negative experiences. He also looked for failures, and describes those.