Will colder temperatures in U.S. make more people sick?

Eugene Texas clears snow from an apartment building he manages as temperatures hovered around 10-degrees, Wednesday Dec. 4, 2013 in Denver. AP

Cold weather has dumped snow, freezing rain and ice across the U.S., from the Southwest  to the Mid-Atlantic to the Northeast. Does that mean this week will be filled with more sniffles, colds and flu cases across the country?

Despite the popular perception that serious temperature drops make you sick, one expert who sees a lot of patients with flu says science doesn’t support such a link.

“It’s really inconclusive,” Dr. Leonardo Huertas, chairman of the emergency department at Glen Cove Hospital in N.Y., told CBS News.

A popular idea is that cold weather diverts energy away from the immune system to warm up the body, but Huertas says the scientific evidence doesn’t support this idea.

What cold weather does is it tends to make people more likely to stay indoors, Huertas explained. More people inside may mean more disease-causing microbes inside, which in turn may raise risk for a person to get sick.

If anything, the cold itself is not causing these microbes to flourish, said Huertas. More evidence suggests the humidity level might be the culprit behind flu and cold illness spikes.

“Cold and flu viruses tend to do better in lower humidity,” he said. Survival rates are higher for the viruses thriving in low humidity, and one Feb. 2013 study found increasing humidity levels indoors may reduce flu transmission, according to LiveScience.

But even that theory has some limitations. A March study found that while flu is more common in temperate areas where the humidity drops, the disease peaks in tropical areas like the Philippines and Vietnam when its hot and rainy, NPR reported.

A bigger predictor for cold and flu season may be the number of people you're exposed to. Huertas notes that large spikes in illnesses like cold and flu are seen around back to school time in September, when the weather is not necessarily cold, just due to the influx of children -- and as such, more germs -- around this time. Disease spikes tend to drop around the December holidays when people flock to winter breaks but pick up again shortly after for this same reason.

More efforts are being made to understand how these outbreaks occur in the hopes of better heading them off.

In Oct. 2012, the World Health Organization unveiled a new tool called the Atlas of Health and Climate to further understand how climate changes trigger disease outbreaks.

Just last month, researchers at the University of Pittsburgh Graduate School of Public Health obtained all data on illness outbreaks that occurred from 1888 through 2013 on flu and more than 50 other diseases in the hopes of preventing future epidemics. The database, called Project Tycho, also tracks vaccines' effectiveness throughout these outbreaks.

While those efforts remain ongoing, Huertas notes there’s one thing you can do now to reduce illness risk around this time of year, and it’s not bundling up in warmer clothing: It's washing your hands.

Cold and flu viruses can live on surfaces like your desk and smartphone anywhere from two to eight hours, according to the Centers for Disease Control and Prevention.

“You don’t think the doorknob you touched 15 minutes earlier, or faucet handle (is the culprit)," said Huertas. “That’s where you tend to get sick.”

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