windows, creating an indoor environment equivalent to a greenhouse with little air circulation and increasing temperatures. Additionally, the mentally ill, who are more likely to be alone because of difficulty in gaining and maintaining social support, may also have difficulty cooling down or avoiding severe sunburns due to their medications. The risks of social isolation incurred by groups such as the elderly and mentally ill are only compounded as neighborhoods evolve and the cultural, ethnic, and linguistic composition of the community changes.

Within the past decade there have been two heat waves with catastrophic results: the Chicago heat wave of 1995 and the European heat wave of 2003. In July of 1995, while the entire Midwestern United States endured an abnormal increase in average temperature, the urban heat island of the Chicago area experienced the highest temperatures recorded since measurements began at Midway Airport in 1928, with daytime temperatures peaking at 106°F. Over 700 people in the city died during this heat wave that lasted about five days.

In the summer of 2003 over 35,000 people died in Europe when an abnormal weather system that lasted for about three weeks aggravated the conditions that had been set in motion by an early and unusually warm spring and low rainfall (Rasool et al., 2004). While the death rate in Chicago from 1995 was actually about identical to the death rate in France, the deaths in Chicago came after two or three days of elevated heat and humidity, whereas the deaths in Europe occured toward the end of the heat wave. Although there is some debate, the delayed deaths in Europe may have occurred due to the temperatures and unusual atmospheric conditions reaching a critical juncture, whereas the conditions in Chicago resulted from a sudden onset of extraordinary atmospheric conditions.

While high temperatures and unusual weather conditions are essential components of a heat wave, there are often a number of compounding issues, such as a lack of communication between government officials and a failure of critical infrastructure. With no official disaster plan in place to address the crisis, the effect of the heat in Chicago was compounded by a number of complicating factors:

• Communications: During a 5-day period in which not only were there 700 more deaths than during a normal period, but also thousands more were hospitalized, some paramedics who first arrived on the scene reported that their own departments refused to release additional ambulances and staff to cope with the workload.