http://www.psr.org/congress-administration/greenhouse-gas-endangerment.html
There are four main categories of health effects.
First - increased frequency and intensity of heat waves. The
associated health problems of heat cramps, heat exhaustion, and
heatstroke will become increasingly common.
Second - increased air pollution. Increased temperatures cause
increased production of ground-level ozone, the main component of
smog. This will increase rates of asthma and other respiratory
diseases.
Third – infectious diseases. Climate change is altering the range of
disease carrying organisms. West Nile Virus, carried by mosquitoes,
was not seen in the US until recently. More than 25,000 cases and more
than 1000 deaths have now been recorded.
Fourth - extreme weather events. These include severe storms,
increases in both drought and flooding, and associated features such
as erosion and wildfires. We do not have the public health capacity to
respond to increasing numbers of large scale disasters that are
difficult to predict.