Hypothermia is defined as a drop in body temperature to less than 94.1° F as a result of exposure to cold weather or a cold natural environment. Without immediate and aggressive efforts to reverse the body’s core temperature loss and restore it to safer levels, hypothermia can quickly lead to a dangerous loss of physical and mental abilities, unconsciousness and death. In Missouri, 569 people have died from the cold since 1979 when hypothermia data collection was first begun by the former Missouri Division of Health. Hypothermia Mortality, Missouri Winter Seasons 1979-2012. The winter season is defined as October 1 to March 31 each year. While data has been collected since 1979, more detailed information regarding cases of hypothermia is available from 1989-2012. Most hypothermia deaths occur during the months of January and December, however, deaths have been reported from September through May. Hypothermia Mortality by Month of Death, Missouri 1989-2012

Senior citizens are often victims of cold-related illness resulting in death. During the winter seasons 1989-2012, a total of 414 hypothermia deaths have occurred, and 186 (44.9%) were people age 65 years and older. Fortunately, deaths from hypothermia in people less than 25 years of age are rare, accounting for only 19 (4.6%) of the total 414 Missouri hypothermia deaths during this timeframe. There have been two (.5%) deaths in children less than five years of age. Hypothermia Mortality by Age, Missouri 1989-2012

Risk factors other than age are present in many of the deaths due to hypothermia in Missouri. In 39 of the 186 (21.0%) deaths of people age 65 and older, debilitating medical conditions were contributing causes. Handicapped or older individuals often fall outside and are unable to reach shelter or help. Individuals with dementia and young children can wander and are unable to find shelter or their way home. People who fall into a body of water, such as a river or lake, during frigid weather can succumb to hypothermia.
Hypothermia Mortality by Age and Risk Factor, Missouri 1989-2012

Substance abuse is often a contributing cause in hypothermia deaths of individuals between the ages of 25-64. From 1989 through 2012, substance abuse was a factor in 107 of the 208 (51.4%) deaths in this age group. Hypothermia Mortality due to Substance Abuse by Age, Missouri 1989-2012. The largest number of Missouri hypothermia deaths was among males, comprising 299 (72.2%) of the 414 total cold related deaths. There were 115 (27.8%) female deaths. Hypothermia Mortality by Race and Sex, Missouri 1989-2012.
The most significant difference in male versus female deaths is found in the 131 deaths due to substance abuse, with 103 (78.6%) male and 28 (21.4%) female. Hypothermia Deaths due to Substance Abuse by Sex, Missouri 1989-2012

The graph Hypothermia Mortality by Risk Factor, Missouri 1989-2012 shows the risk factors for the 407 people who have died in Missouri from hypothermia from 1989 through 2012. Of the 414 deaths, 23 (5.6%) are shown as “other.” These 23 include: drivers whose motor vehicles became disabled during a winter storm or who were injured in a motor vehicle accident during cold weather; people involved in homicidal or other criminal activity; individuals who participated in outdoor occupational or recreational activity; people who committed suicide; residents whose furnaces were inoperable, including power outages due to storms; and children who wandered and were lost outside.

Jackson County, St. Louis County and St. Louis City accounted for 44.2% (183) of deaths with 55.8% (231) occurring in other areas of Missouri. Hypothermia Mortality by Geographic Area, Missouri 1989-2012 The geographic distribution of hypothermia deaths from 1989 to 2012 shows that there was one or more death from cold weather exposure in 83 of Missouri's 114 counties and St. Louis City. Hypothermia Mortality by County, Missouri 1989-2012

Since 2006, Missouri has also been using the Electronic Surveillance System for the Early Notification of Community-based Epidemics (ESSENCE) software to collect emergency department (ED) data.  ESSENCE data do not represent all cases of hypothermia among Missouri residents or all cases of hypothermia among patients visiting ESSENCE hospital EDs. These data represent all ED visits among ESSENCE hospitals with the keywords “hypothermia,” “therm” or “cold exposure” contained within the chief complaint recorded upon admission to the ED. Currently 90 hospitals contribute data to ESSENCE. For more information, see this visit the Essence website.

During the winter season 2009-2012, ESSENCE indicates there were 295 Missouri residents who visited emergency departments due to cold weather exposure.

Missouri is the only state that conducts on-going statewide surveillance for cold weather-related illnesses and deaths. Health care providers are required to report cases of hypothermia to the Missouri Department of Health and Senior Services.