Hyperthennia is rapidly becaning the fourth IIDdality of cancer treatment, at least a useful adjuvant to radiation therapy, chEfiO- therapy or surgery; at best, a new therapeutic fonn that, properly used, may open new horizons in the fight against this dreadful disease. The staging is still primitive. The devices used are after laboratory irrprovisations, and lack the precision and definition of treatment fields that will allow mass use of the m:Xiality. Clinical practices are limited to the procedural evaluations of a few pioneer groups, and basic understanding of its mechanism of action, although progressing by leaps and bounds, is still short of perfection. The challenge and the pranise are there and because of this, p engineers, physicists, biologists, physiologists and clinicians fran different specialties have a basic need for interaction, both in tenus of exchange of scientific infonnation and peer review of results and clinical trials. To satisfy this need, to act as a clearinghouse of knowledge and a fonnn for discussion, the North Alrerican Hyperthennia Group (NAHG) has been fonned. The!reeting in Detroit in August 1981 represents the first gathering of the group, to be followed by a second in Salt Lake City in April 1982.