TUESDAY, July 12 (HealthDay News) -- Scorching heat and
oppressive humidity continued to grip much of the United States
Tuesday, with temperatures exceeding 90 degrees -- and in some
cases 100 degrees -- from the Southwest to the Northeast.
The heat wave is prompting doctors to warn that high
temperatures can cause serious -- and potentially fatal -- health
"The body has ways of keeping itself cool, by letting heat escape through the skin, and by perspiring," said Dr. Ken Sable, vice chair of emergency medicine at Maimonides Medical Center in New York City, where the mercury was expected to top out at 95 degrees on Tuesday.
"If the body does not cool properly or does not cool enough, the victim may suffer a heat-related illness. Anyone can be susceptible although the very young and very old are at greater risk. Heat-related illnesses can become serious or even deadly if unattended," he added.
Dr. Janyce Sanford, chair of emergency medicine at the
University of Alabama at Birmingham Hospital, said heat-related
illnesses span a range of ills, from mild to severe. "Someone who
has been working out in the heat may start to experience the
beginning stages with heat cramps. As it progresses, the next step
is heat exhaustion. They may develop a severe headache, nausea,
vomiting, and a feeling of severe weakness," she said in a
university news release.
The most serious -- and potentially fatal -- heat-related
illness is heat stroke, Sanford said.
"When you reach this point, the severely elevated body temperature causes an altered mental state, dizziness and ultimately can lead to a loss of consciousness. The muscles can start to break down, which leads to kidney failure; this makes heat stroke a life-threatening illness," she said.
Though rare, heat stroke is most often seen in very young and
elderly people, or people with a chronic illness.
Sable said the safest place to be during a heat wave is indoors
-- if air conditioning is available. Remain in the air-conditioning
as long as possible. And limit outdoor activity to morning and
evening hours when temperatures are relatively cooler.
Sanford offers the following advice:
- Avoid being outside during the hottest part of the day, 11 a.m.
to 4 p.m. Wear light-colored and lightweight clothing, a hat, and
remember that 100 percent cotton clothing tends to hold sweat,
making it harder for your body to cool off.
- Thirst isn't always a good sign of hydration status. In
children, the thirst mechanism isn't fully developed, and in
seniors, the sense of thirst has diminished. By the time your brain
signals thirst, you may have lost 1 percent of your body weight --
about 3 cups of sweat for a 150-pound person.
- Urine color is an important indicator of hydration. A
well-hydrated person's urine will be almost clear. Darker colors
indicate less hydration. Not having to urinate at all after intense
workouts is a warning sign of real dehydration.
- If you exercise for less than 90 minutes at a time, cool water
(40 degrees F) is all you need to replace fluids. You should drink
about 16 ounces of water two hours before exercising, eight ounces
every 15 to 20 minutes during exercise, and then at least another
16 ounces after finishing. Drink until your thirst is quenched, and
then drink even more to fully rehydrate.
- Sports beverages are appropriate if you're exercising for more
than 90 minutes. These beverages should be consumed only during
exercise and not before, because they might trigger a hypoglycemic
-- or low glucose -- effect, potentially reducing performance.
Sable said it's also best to avoid caffeine and alcohol. Drinks
that contain caffeine, alcohol, or large amounts of sugar can cause
dehydration and irritability.
The National Weather Service said the excessive heat would
continue over much of the eastern two-thirds of the country on
Tuesday, with excessive heat warnings and heat advisories in place
from parts of Texas and Oklahoma, eastward across the Plains states
and Mississippi Valley, into the Gulf Coast states, southeastern
United States, and the Mid-Atlantic region. Air quality alerts are
in effect across the eastern United States, including parts of New
Jersey, Pennsylvania, Maryland, Virginia, North Carolina, and
The cause of the heat wave is a high-pressure system that has
remained stuck over much of the middle of the country, blocking the
arrival of cooler air from Canada. In Wichita, the temperature has
hit at least 100 degrees for 20 straight days.
If you're looking for some (very) long-range relief from the
heat, don't count on it. A recent study from Stanford University
predicts that scorching temperatures would become the new norm,
with unusually hot summers by the middle of the century. The
culprit cited by the researchers: global warming.
For more on protecting yourself from the heat, visit the
U.S. Centers for Disease Control and