Wellness: Prevention  No Sweat? No Good!  In the heat of summer,
it's important to exercise with caution and pay attention to
your body. Even if you're fairly well conditioned, overdoing it
may lead to heat cramps, heat exhaustion or heatstroke, causing
the body to lose its ability to sweat.  Age plays an important
role in heat-related illnesses. Because older adults and people
with chronic illnesses aren't able to sweat as easily as healthy
younger adults, they are more susceptible to heat-related
illnesses. Infants, young children, people who are obese, and
people who have a mental illness are also more susceptible to
heat-related illnesses.   Heat-related illnesses can be
classified into three categories: heat cramps, heat exhaustion,
and the most severe, heat stroke. (A fourth category, heat
injury, is similar to heat stroke without central nervous system
dysfunction).  Heat cramps  Heat cramps are painful muscle
spasms that occur after strenuous activity that produces a lot
of sweat. Sweating causes a lo