Hypothermia, especially in an urban environment, is often an unsuspected and therefore underdiagnosed clinical entity. Of 60 cases recorded over a two-year period in a typical community hospital in Philadelphia, 26 (43%) involved patients under 60 years of age; ambient air temperatures at admission exceeded 50 F (10 C) in 28 (47%) of the 60 cases. Hypothermia thus cannot necessarily be attributed to advanced age or cold climates or seasons. The severity of hypothermia did not correlate with either the season of the year or the ambient air temperature. Diabetes and alcohol abuse appear to be risk factors for hypothermia, being present in 18 (30%) and 14 (23%) of our patients, respectively. Every emergency department should have a protocol for identification and management of the hypothermia victim to allow timely institution of appropriate rewarming techniques.