Both increased heat and increased air pollution will cause more deaths in cities. In most cities, higher temperatures mean more air pollution. Heat facilitates the formation of ground level ozone - a primary ingredient of urban smog. As temperatures peak in cities, so do ozone levels. Smog inevitably results.
Smog aggravates respiratory ailments such as emphysema and asthma.
Children and older adults are especially at risk. That doesn't include those who suffer without being hospitalized. The heat wave which hit North American cities during the summer of 1988 may be a harbinger of what is in store. Central and western Europe experienced similar heat waves in 1992. Hundreds of Americans died in the blistering heat wave that engulfed the eastern United States in the summer of 1995.