Extreme Heat

Extreme Heat

Few American cities are adequately prepared for the excessive heat we can expect with global warming.

In 1995, a heat wave killed more than 700 people in Chicago, many of them the elderly poor. Such a catastrophe could happen again, says Marie O’Neill, assistant professor of epidemiology and environmental health sciences and an expert on climate change and health. Thanks to global warming, future heat waves are likely to be even worse—more frequent, longer-lasting, and more intense.

Few American cities are adequately prepared. Only 20 to 30 cities in the United States have surveillance systems to warn citizens about the dangers of extreme heat. Older people are especially vulnerable, O’Neill says, because they often live alone, and many suffer from respiratory diseases and other ailments that make it difficult for them to thermoregulate. The communities where they live can also have an impact. Are neighborhoods people-friendly, or do residents stay inside—and therefore risk being forgotten in a crisis—because the streets are unsafe?

With a grant from the Environmental Protection Agency, O’Neill and a team of researchers are looking at ways to improve preparedness. They want to see, for example, if air pollution, in combination with heat, increases the risk of morbidity. What effect does latitude have? Green space? Are there effective community programs in place, such as tree-planting or painting roofs white? Are there cooling centers for people who lack access to air conditioning? Perhaps most importantly, is there a heat-wave warning system?

“We’re trying to see if city-level activities can reduce risk for the elderly,” O’Neill says. Eventually she and her collaborators will conduct nationwide workshops to heighten preparedness.

Paradoxically, one of the best ways to combat heat—air conditioning—is also one of the greatest contributors to global warming, since the electricity used often comes from fossil-fuel combustion. “Air conditioning is one part of the solution, but it’s not really a sustainable strategy for addressing this problem,” says O’Neill. “We need to reduce human contributions to future climate change while preparing our society to adapt to and prevent the health consequences of the now-unavoidable changes already underway.”

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factCHECK, 2007

  • Extreme heat caused 35,000 deaths in Europe in August 2003
  • Groups most vulnerable to extreme heat include the elderly, infants under one, the homeless, the poor, people who are socially isolated, people with mobility restrictions or mental impairments, people taking certain medications (e.g., for high blood pressure, depression, insomnia), people engaged in vigorous outdoor activity, and those under the influence of drugs or alcohol
  • Medical conditions directly attributable to excessive heat exposure include heat cramps, heat exhaustion, and heat- or sunstroke