Hypothermia, defined as a core body temperature of <95 degrees F (35 degrees C), occurs in persons exposed to excessive cold. Although hypothermia can be fatal, it also is preventable. Risk factors for death from hypothermia include advanced age, substance abuse, altered mental status, and increased contact with substances that promote heat loss, such as water. Montana has an intensely cold and long winter. In December, the average daily minimum temperature is approximately 18.0 degrees F (-7.7 degrees C) and can remain at that level until March. For the entire year in Montana, the average daily minimum temperature is 35.9 degrees F (2.2 degrees C). During the period 1999-2004, Montana had the second highest (after Alaska) average annual hypothermia-related mortality rate (1.08 deaths per 100,000 population) in the United States, approximately five times greater than the U.S. rate overall. This report describes three examples of case reports of hypothermia-related deaths in Montana during 2005-2006, summarizes hypothermia-related mortality in the state during 1999-2004 (the most recent period for which annual data were available), and discusses hypothermia risk factors and prevention measures. Enhanced education and intervention strategies, particularly targeted to older adults, might reduce the number of deaths from hypothermia in Montana.