FRIDAY, Aug. 3, 2012 (HealthDay News) -- Heat waves are more deadly than even the most devastating hurricane, blizzard or tornado, evidence indicates.
Richard Keller, a professor of medical history at the University of Wisconsin-Madison, analyzed the 2003 heat wave that descended over parts of Europe and claimed the lives of 70,000 people. The high-pressure system resulted in the hottest weather in more than 500 years, he found. The extreme heat melted electrical cables, liquefied museum specimens, prevented nuclear reactors from being cooled and caused water pumps to fail.
France was hit particularly hard by the heat wave, facing temperatures above 100 degrees Fahrenheit on seven days, Keller noted. According to official records, more than 14,800 people died in Paris alone. The extreme heat occurred during a time when many government officials and physicians were on vacation and unclaimed bodies overwhelmed undertakers and mortuaries.
To put that heat wave into perspective, Keller compared its effects to the devastation of Hurricane Katrina that occurred two years later. The floods resulting from the hurricane that hit New Orleans and the Gulf Coast in 2005 killed 1,836 people.
Keller pointed out that the death toll during the 2003 heat wave was exacerbated by variables, such as victims' age, social status and gender. He explained that many elderly women who lived alone in poorly ventilated walk-ups in Paris succumbed to the heat.
"People who lived in these apartments died like flies," Keller said in a university news release. "This was as much a social as a health and epidemiological disaster. There were social factors that made some people much more vulnerable."
Older people are at greater risk from heat-related illnesses because they often don't notice the effects of dehydration, he warned, and many of the medications older people take could worsen the effects of extreme heat.
Living alone was another factor that contributed to deaths during the heat wave. "The single biggest factor for dying was if you lived alone," Keller said.
"Vulnerability to extreme events is more complex than we know and we need to think about broader-scale adaptation," Keller concluded. "We have to recognize that heat kills far more people than the cold and that those most likely to die are people on the social margins of society."
The U.S. National Library of Medicine has more about heat-related illness.