Hyperthermia

The Missouri Department of Health and Senior Services monitors high temperatures and humidity across the state to 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 anti-psychotics, major tranquilizers, antihistamines, over-the-counter sleeping pills, antidepressants, heart drugs and some anti-Parkinsonian agents. Each year many Missourians suffer from heat-related illnesses, with some cases resulting in death. During prolonged periods of high temperatures, air conditioning is the best preventive measure.

The former Missouri Division of Health initiated statewide hyperthermia death surveillance in 1980 in response to a summer heat wave that resulted in the death of 295 individuals due to Missouri’s extreme weather temperatures. Hyperthermia Mortality, Missouri 1980-2007. This surveillance program defines hyperthermia as physician-diagnosed heat exhaustion, heat stroke or hot weather/natural environment as a contributing factor in a death.

Slightly more than half of Missouri's heat-related deaths have occurred in the urban, more densely populated areas of St. Louis City, St Louis County and Jackson County (Kansas City). From 2000 through 2007, of the total 194 deaths, there were 121 (62%) deaths in these metropolitan areas. Rural deaths accounted for 73 (38%) of the deaths, including the death of one Kansas resident while at a Missouri recreational area in August 2003 and the death of an Arkansas resident while working in Missouri in July 2006. Hyperthermia Mortality by Geographic Area, Missouri 2000-2007. White males are the most frequent victims of heat-related illness resulting in death; there were 93 (49%) white male deaths from 2000-2007. Hyperthermia Mortality by Race and Sex, Missouri 2000-2007.

The greatest number of deaths 106 (55%) during 2000-2007 have been of people age 65 years and older. Victims in this population are often individuals living alone who have other complicating medical conditions. Also, lack of air conditioning or fear of higher utility expenses from air conditioner use contributes to the number of deaths in the senior population. There were 88 (45%) hyperthermia deaths occurring in the 5 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 2000-2007, there were 11 (6%) deaths of children less than five years of age. Hyperthermia Mortality by Age, Missouri 2000-2007 and Hyperthermia Mortality by Contributing Factor & Geographic Location of Death, Missouri 2007 and Hyperthermia Mortality by Contributing Factor, Missouri 2007

 
In August 2007, Missouri experienced a heat wave that lasted approximately 21 days.  The heat wave started August 2 with a heat index of 101 in Cape Girardeau and spread across the state.  By August 7, five National Weather Service (NWS) Forecast Offices reported that the majority of the state was experiencing heat indices of 103 degrees Fahrenheit or higher.  The heat index remained in the upper 90’s or higher in at least one of Missouri’s six NWS forecast areas until August 25. Public and private emergency response plans were implemented across the state. These responses included opening cooling shelters, distributing ice, water, and people checking door-to-door for persons in danger from the heat. Without this quick and intensive response, public health officials believe mortality from the August 2007 heat wave would have been much greater.

On average, approximately half of the hyperthermia deaths in Missouri in any given year occur in the month of July. However, in 2007, 24 (71%) of the 34 hyperthermia deaths in Missouri occurred during August. One (3%) death occurred in June, six (18%) deaths occurred in July and three (9%) deaths occurred in September. 

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.