Aug. 11, 2006
 
HEALTH: Why Air Conditioning Might Make You Fat…or Sick
 
By Lee Bowman
Scripps Howard News Service
 
Is air conditioning bad for our health?
 
While it may sound like a silly question for Americans who've endured heat waves and power outages this summer, there's evidence that artificial chills produce at least some ill effects.
 
Some problems, such as respiratory infections and allergic reactions to molds and other crud that can accumulate in poorly maintained air-conditioning systems, are well-documented. The first cases of Legionnaires' Disease linked to a building's cooling system were documented 25 years ago this summer.
 
Similar contamination problems can also affect air-conditioning systems in cars and trucks -- usually the result of blocked vents or drains that keep moisture trapped so that germs can breed.
 
There's also considerable evidence that closed ventilation systems in office buildings and other workplaces can result in "sick-building syndrome," which makes some, and sometimes many, people inside have trouble breathing, become nauseated, have headaches or suffer other symptoms.
 
But a lot of the health problems associated with AC may arise when the systems are working perfectly well. Maybe too well.
 
According to a survey done by the International Facility Management Association, the No. 1 gripe from building tenants is that "it's too cold." And the second-most-common complaint is that "it's too hot."
 
Experts say the trend in many offices is to overchill, in part because of the need to cool not just people, but also computers and other electronics that give off a good deal of heat. Moreover, adults with a higher percentage of body fat -- or high blood pressure -- tend to want it cooler around them, and that means about two-thirds of Americans are likely to push down the thermostats.
 
But that can leave the remaining third with low levels of body fat or low blood pressure freezing inside during the summer and early fall, especially if they've dressed lightly for the seasonal temperatures outside.
 
Veterans of intemperate zones at workplaces cope by keeping a sweater or sweatshirt at their desk, but they may also need the extra layer at restaurants, movie theaters and other public places.
 
Renee Grant-Williams, a Nashville, Tenn.-based voice coach, says transitioning quickly between hot and cold spots puts a strain not just on the vocal chords, but the entire respiratory system.
 
"Rapid changes in body temperature seem to make many people susceptible to lingering summer colds, sinus problems and other respiratory ailments that can be difficult to shake," she said.
 
Moreover, returning to the heat can be made more dangerous if the body isn't given time to acclimate.
 
"In the past, the typical people who used to get in trouble (with the heat) were the ones who couldn't fend for themselves -- the very young and the very old," said Dr. Paul Pepe, head of emergency medicine at the University of Texas Southwestern Medical Center in Dallas.
 
"But what we see a lot of today are the young weekend warriors who have been in super-cool environments all week and get out, exercise and get into trouble."
 
That's why many coaches and athletic trainers recently have urged athletes heading into August workouts for football, cross country and other demanding fall sports to do light workouts every day for an hour or two on their own for several weeks before practices begin, preferably wearing the same clothing, even minus pads and helmets.
 
Other researchers have even suggested that air conditioning is somewhat responsible for the obesity epidemic itself.
 
Normally humans, like all mammals, expend energy to maintain an acceptable body temperature, not too cold or too hot. Dogs pant, people sweat. But by spending most of their time in climate-controlled environments, people are expending less energy keeping cool, and that helps add on pounds.
 
David Allison, a researcher at the University of Alabama-Birmingham, said in a recent paper in the International Journal of Obesity that it's not coincidence that the rise of obesity in this country has largely been in sync with the growing prevalence of air conditioning over the last 30 years or so.
 
Moreover, he noted, people tend to eat less when they're hot.
 
"If you lived in Alabama in the summer of 1960, without air conditioning in a car or restaurant, you probably wouldn't want to go to an all-you-can-eat buffet," he said.
 
On the Net: http://www.bt.cdc.gov/disasters/extremeheat/faq.asp
 
Contact Lee Bowman at BowmanL@SHNS.com.
 
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