Billions suffer from colds every year, and because so many colds occur in the winter time, there has always been a sense that cold weather causes colds. Fact or fiction?

In fact, a recent, small study from the UK.'s Common Cold Centre in Wales found that when people were exposed to a chill they came down with cold symptoms at double the rate of those study participants who kept warm. But there was no difference in the severity of cold symptoms.

That's because people who are exposed to the cold experience a constriction of blood vessels in their noses, which shuts off warm blood from nourishing the white cells that fight infection, the study's authors said.

"The reduced defenses in the nose allow the virus to get stronger and common cold symptoms develop," study author Ron Eccles, of Cardiff University, said in a prepared statement.

But, he added, "although the chilled subject believes he has 'caught a cold,' what has in fact happened is that the dormant infection has taken hold."

"As body temperature drops, the body fights infection less well, so the two could be related," said Jordan Josephson, director of New York Nasal and Sinus Center in New York City.

Not everyone agrees that staying curled up in front of a warm fire is the best remedy for a cold, however.

"Whatever compromises your own immune system would put you at risk, [but] outdoor air dilutes the cold viruses," said Jean Pfeiffer, a faculty member at the University of Minnesota School of Nursing in Minneapolis and longtime expert in infection prevention and control. "A lot of health professionals believe that being outdoors is healthy for you."

Pfeiffer added that cold viruses are also very easily spread indoors. Every time a person sneezes or even speaks, they release large droplets that contain the virus, and these are carried to others both by the air and by touching surfaces infected by these droplets.

According to the Minnesota expert, indoor gatherings of people -- which are more common in cold weather -- are probably the most likely breeding grounds for colds.

No matter what the source of a cold, however, prevention is key, because once a cold sets in it usually lasts for three to five days and sometimes longer, causing absenteeism from both work and school. The U.S. Centers for Disease Control and Prevention estimates that 22 million school days are lost every year due to colds.

The most effective way to lower the risk for colds is to observe some rules of basic hygiene, Pfeiffer said.

Wash your hands often with soap and water, using your own towel to dry them. Keep your hands away from your face -- this stops any handborne virus from reaching the mouth. And don't share glasses, dishes or silverware.

"Use tissues freely," Pfeiffer added.

If someone has a cold, keep at least three feet away from them. If that's not possible, -- for example, in the case of a mother taking care of a baby -- wash your hands as often as you can. People should use an alcohol-based hand gel that kills germs if soap and water is not available, Pfeiffer said.

And if you have a cold yourself, do your friends, family and colleagues a favor by staying home if possible, so you don't infect others.

While there is no antibiotic cure for a cold, sufferers do have tools to speed its progress, Pfeiffer said.

"Keep well-hydrated so your system will be flushed. The sinuses will be more open, and it does a lot [to ease discomfort]," Pfeiffer said. She recommended drinking a cup of liquid every hour so that urine remains clear.

Other health professionals believe that taking over-the-counter antihistamines, decongestants and pain relievers like ibuprofen at the first sign of symptoms can also help relieve the burden.

It's also important, to make sure that what you've got is a cold.

"A cold is a layman's term for not feeling well," Josephson said, but you could have other illnesses that need treatment, such as an infection, allergies or recurrent sinusitis.

Common cold symptoms include a runny nose, scratchy throat, congestion, a cough and that general rundown feeling, he added.

However, mucus that is yellow or green rather than clear could point to a bacterial infection that needs to be treated with antibiotics, he said.

Allergies can also mimic cold symptoms. Sudden sneezing jags could mean you're having a reaction to fall allergens. "Sneezing is a reaction to particles inside your nose that are saying, 'Get me out,'" Josephson said.

Itchy eyes or dark circles under the eyes are also symptoms of allergies rather than colds.

"And if you have a cold every two months, it's not a cold but rather chronic sinusitis," Josephson said, and you should see a doctor.

- More articles on Cold Prevention

Reference Source 101
November 24, 2005