Data & Statistical Reports

Each year many Missourians suffer from heat-related illnesses, with some cases resulting in death. During prolonged periods of high temperatures, using air conditioning–either at home or by seeking shelter in a local cooling center–is the best preventive measure.

The Missouri Department of Health and Senior Services monitors high temperatures and humidity across the state in an effort to help prevent heat-related illness and death. The elderly and the chronically ill are more vulnerable to the effects of high temperatures. They perspire less and are more likely to have health problems requiring medications that can impair the body's response to heat. Many prescription medications make individuals more sensitive to the heat. Some of these medications include heart drugs, some anti-Parkinsonian agents, antihistamines, over-the-counter sleeping pills, antidepressants, anti-psychotics and major tranquilizers.

The former Missouri Division of Health initiated statewide hyperthermia death surveillance in 1980 in response to a heat wave that resulted in the death of 295 individuals due to Missouri’s extreme temperatures that summer. Hyperthermia Mortality, Missouri 1980-2013This surveillance program defines a heat-related death as a death for which a coroner or medical examiner includes hot weather exposure as the underlying cause or a contributing cause on a death certificate. From 1980 through 2013, there have been 1,075 deaths caused by Missouri’s hot weather and high humidity.

In Missouri, the greatest numbers of heat-related deaths have occurred in the urban, more densely populated areas of St. Louis City, St Louis County and Jackson County (Kansas City). Of the 358 heat-related deaths reported from 2000 through 2013, there were 217 (61%) deaths in these metropolitan areas. Rural deaths accounted for 141 (39%) of the deaths. Non-Missouri residents who succumb to heat while visiting are considered cases, accounting for 11 deaths.
Hyperthermia Mortality by Geographic Area, Missouri 2000-2013
Number of Heat Related Deaths in Missouri by County for 2000-2013
White males are the most frequent victims of heat-related illness resulting in death. In the same twelve-year period, there were 171 (48%) white male heat-related deaths. Hyperthermia Mortality by Race and Sex, Missouri 2000-2013

Half of the 358 deaths during 2000-2013 have been of people age 65 years and older. Victims in this population often live alone and have other complicating medical conditions. Also, lack of air conditioning or refusal to use it for fear of higher utility expenses contributes to the number of deaths in the senior population. There were 163 (46%) hyperthermia deaths occurring in the 5 year through 64 year-old age group. These deaths often have contributing causes such as physical activity (sports or work), complicating medical conditions, or substance abuse. Circumstances causing hyperthermia deaths in young children often involve a motor vehicle—a child left in or climbing into a parked vehicle during hot weather. From 2000-2013, there were 15 (4%) heat-related deaths of children less than five years of age.
Hyperthermia Mortality by Age, Missouri 2000-2013
Hyperthermia Mortality by Contributing Factor & Geographic Location of Death, Missouri 2007-2013
Hyperthermia Mortality by Contributing Factor, Missouri 2007-2013

Missouri’s highest temperatures generally occur in July and August each summer. Thus, the majority of hot-weather-related deaths also occur during these months. Of the 358 deaths from 2000-2013, 171 (48%) deaths were during the month of July and 115 (32%) were in August.
Hyperthermia Mortality by Month of Death, Missouri 2000-2013
During heat waves, varying public and private emergency response plans are implemented across the state. These responses include opening cooling centers, distributing ice and water, and people checking door-to-door for persons in danger from the heat. Without these local response actions, public health officials believe mortality from hot weather would be much greater.

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

Note: 2013 data is preliminary