In the heat of the summer : lessons from the heat waves in Paris.

Climate change and human health are intertwined. The heat waves in Chicago, in 1995, and in Paris, in 2003, followed by Hurricane Katrina_s destruction of New Orleans, raised awareness of the risks faced by vulnerable older people. Many cities have responded by announcing emergency preparedness plans; some of these plans have already been tested. Last summer, from July 27 to August 5, New York City suffered a mild heat wave with temperatures reaching 100-F. Paris, as well, was hit by another heat wave from July 17 to July 29, with maximum temperatures reaching 104-F, which was considerably milder than in 2003 when they often exceeded 110-F. In New York, there were 100 Bexcess deaths,^ an increase of 8% over past trends. In Paris, the number of excess deaths in 2006 (42), also an increase of 8%, was considerably lower than the 1,294 deaths registered in 2003—an increase of 190% compared to the preceding three-year average. Given existing surveillance capacity, it is impossible to know whether the reduction in excess deaths in Paris was due, partly, to its enhanced preparedness or whether it reflects no more than the effects of a far milder heat wave. Nevertheless, the milder heat wave of 2006 does provide an opportunity to examine the actual implementation of the heat wave preparedness plan. In light of ongoing efforts to develop such plans in cities worldwide and completed studies on the effects of the 2003 heat wave in Paris, what may be learned to promote urban health and improve understanding of the factors that put vulnerable older people at greatest risk?