In a typical year, heat claims about 240 victims in the United States. In four days ending Monday, heat killed 179 people just in Cook County. And with hundreds of bodies awaiting autopsy, the final toll was expected to exceed 300.
So the question is this: Was the Chicago disaster a freak of nature or a twist of statistics?
“I don’t think we’re dramatizing this one bit,” said Dr. Edmund Donoghue, Cook County medical examiner.
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Donoghue, whose office is performing the autopsies, brushed aside suggestions Monday that he is looking especially closely for heat-related deaths and is too quick to list heat stress as a cause of death.
“I was chief medical examiner of Cook County last year and this year,” he said. “We didn’t look any harder last year, and we came up with five (heat-related deaths). This year, we’ve got 179 so far.”
Coroners disagree about when heat becomes deadly, so pathologists use their judgment, along with their reference books, when making a call.
Accordingly, Donoghue said Monday that he had set his own, admittedly liberal “Chicago criteria” before declaring someone a heat-related fatality: a body temperature of at least 105 degrees, a sweltering apartment and a little deduction.
“When you’re faced with hundreds of cases, this is not an unreasonable approach,” he said. “There isn’t necessarily a protocol. You have to use a modicum of common sense in that we’ve got all of these excess deaths and it’s been very hot.”
Dr. John Wilhelm, chief medical officer of the Chicago Department of Health, said Donoghue may be “liberal in his position.”
“That may explain why, if another city has an equal amount of heat, we’re seeing more heat-related deaths here.”
In this age of air conditioning, the Chicago area was stunned to discover that so many people could die from the heat. Donoghue said none of the 179 victims, most of whom were elderly, had air-conditioned homes.
Suburban counties attributed few deaths to the five-day heat wave, which began Wednesday and saw temperatures soar to 106. McHenry, Will and DuPage reported none. Kane County reported five, all from Aurora. And Lake County authorities said 16 fatalities might be related to the heat.
Lake County Coroner Barbara Richardson takes a much more conservative approach to determining cause of death than does Donoghue.
“There’s no way you’re going to get me to say that definitely these were heat deaths,” she said. “If it’s 20 degrees below zero and someone dies of a heart attack, is that a cold death or a heart attack death? It’s a judgment call.”
Determining a cause of death, especially from something such as heat stress, can be subjective.
Unlike violent natural disasters such as blizzards, tornadoes and earthquakes, heat is a slow, insidious killer that strikes vulnerable people who usually are isolated, helpless and alone. The urban poor, in small, hot high-rises are especially vulnerable, which may explain why so many in Chicago died.
“Prolonged periods of very hot weather claim more lives nationally than any other natural disaster, including floods, tornadoes and hurricanes,” asserted a report from the U.S. House Special Committee on Aging.
Extremely high temperatures cause approximately 240 deaths in the U.S. each year when there are no heat waves, according to the federal Centers for Disease Control and Prevention (CDC) in Atlanta.
However, in years when hot spells did occur, they have been blamed for as many as 1,700 deaths. Death rates tend to be highest in Alabama, Arkansas, Arizona, Georgia, Kansas, Mississippi, Missouri, Oklahoma and South Carolina.
Specialists dispute the exact body temperature at which heat stress or heat stroke occurs. Some coroners, for example, will not blame the heat unless they can take the deceased’s body temperature upon death-which is not always possible-and that temperature must be at least 106 degrees.
Other medical examiners are reluctant to blame the heat when the deceased has a chronic medical condition-even if death occurred on a record-hot day.
Donoghue conceded that most of the Cook County dead were not in prime health. But he acknowledged that fact by listing the underlying medical condition as the primary cause of death, and heat stress as a secondary reason.
“These people were probably very near death and their date of death was just moved up by the heat,” Donoghue said. “How long they would have lived, we can’t tell you.”
Because no unified national reporting standards exist, many scientists suspect that far from being inflated, the reported death tolls from heat may be drastically understated.
For example, patients suffering from cardiovascular and respiratory disorders are much more likely to die during heat waves, but their deaths are rarely attributed to the weather.
Researchers have struggled to get a handle on the situation. So far, they say, Chicago’s high death toll-though dramatic and surprising-is probably accurate.
“I support the Chicago medical examiner’s estimates a thousand percent,” said one expert, University of Delaware geography professor Larry Kalkstein. “I think everybody else estimates heat-related deaths too conservatively.”
In 1993, for instance, the Philadelphia medical examiner was criticized for attributing too many deaths-118-to extreme high temperatures.
He took the same approach as Donoghue.
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Reacting to criticism, Pennsylvania health officials asked the CDC to conduct an investigation that attempted to pinpoint cause of death in all cases.
“We found that the Philadelphia medical examiner was correct,” said Dr. Sherri Wainwright, an epidemiologist with the CDC who worked on the study.
In fact, twice as many people died of cardiovascular causes associated with the heat wave than would have been expected to die during a normal summer, the CDC estimated.
Doctors agree, however, that pre-existing medical conditions or substance abuse can complicate the diagnosis of death from heat stress. Cocaine, for example, can raise body temperature and make the heart beat faster, which makes drug use especially deadly during a heat wave.
If someone dies of a cocaine overdose during a heat wave, what is the most accurate way to label that death?
“It’s tough to say, isn’t it?” said Dr. Jeff Schaider, an emergency room physician at Cook County Hospital. “It’s sort of a combo deal.”
A CDC study of deaths in St. Louis and Kansas City during the July 1980 scorcher that killed 1,700 people nationwide found the heat death rate for people aged 65 had skyrocketed to 48.7 per 100,000, compared with just 3.8 per 100,000 for those under 65.
St. Louis has had an emergency plan in place since 1981, according to Nancy Buechler, city health promotion director. “Heat is a reportable illness here,” she said.
“We do everything we can to convince people that heat is a killer,” Buechler said.
“Unfortunately, you always have a segment of the population that is isolated,” she said. “If you in Chicago can figure out a way to reach these people, please let us know.”