Colds are more common in the late fall and winter for a few reasons.

For one thing, when the weather cools, we spend less time in fresh air and more time indoors, so we’re more likely to inhale the germs that other people carry and spread when they sneeze and cough.

Another reason? When the temperature drops outside, we tend to crank up the heat inside. Heat dries the air, which can then dry out our nasal passages and sinuses.

When the nasal passages and sinuses dry out, either they don’t produce enough mucus or the mucus becomes too thick and can’t drain, making germs more likely to cause infections.

But keeping your sinuses moist, especially in cold months, helps protect you, according to Jordan S. Josephson, MD, director of New York Nasal and Sinus Center in New York City and author of Sinus Relief Now (Perigee Trade), who recently told me about some easy ways to do this.

A CONTROVERSIAL TOPIC

Before we jump into Dr. Josephson’s advice, it’s worth noting that not all experts agree on this issue. In fact, you might remember a 2010 Daily Health News article that reported on a study that found that people who irrigated their sinuses—one of Dr. Josephson’s suggestions—had more sinus infections than those who didn’t. But Dr. Josephson disagrees with those findings, because over the past two decades, he has recommended sinus irrigation to tens of thousands of his patients, and almost every one of them has told him that it has helped ward off sickness.

BEST WAYS TO IRRIGATE THE SINUSES

Here are the top techniques that’ll keep your sinuses moist, according to Dr. Josephson, who has no financial interest in the following products…

Most people find the greatest relief from using a neti pot, which looks like a little teapot. Every day, fill it with sterile water and salt (premeasured packets usually come with the neti pot, or you can buy them separately). Then, with your head tilted over the sink, insert the spout into one nostril and let the water flow. Most people pour all the water at once, slowly, but you can start with a little at a time if it feels better. Gravity sends the salt water through the nasal cavity and sinuses and out the other nostril. Dr. Josephson recommends the NeilMed NasaFlo neti pot, which is available in drugstores and at Drugstore.com for about $15. Be sure to use only distilled water that you have boiled to sterilize and have cooled to room temperature, because as you might remember from this Daily Health News article from February 2012, using unsterile water can potentially lead to a deadly infection.

For people with especially thick mucus or crusty nasal passages who find that the neti pot isn’t working, Dr Josephson said to try using the Grossan Hydro Pulse, which might be a better option. It’s more expensive, but this electric appliance sends pulses of saline into the sinuses and breaks up thick or crusty mucus. It sells for about $78 in drugstores and on www.HydroMedOnline.com.

If the neti pot and the Hydro Pulse sound too expensive or too hard to use, irrigating with a saline nasal spray is a decent choice. But a spray’s effect isn’t as long-lasting, so you need to use the spray several times a day. Dr. Josephson recommends a brand called Little Noses by Little Remedies Saline Spray/Drops (it’s a dropper when you hold it upside-down and a sprayer when you hold it right-side up, and it costs about $4 for one ounce) or Ayr Saline Nasal Mist (about $3 for 1.69 ounces). They’re available in drugstores or on Drugstore.com. He also likes Ultra Saline Nasal Mist from Goldberger’s pharmacy ($5 for two ounces) from store.GoldbergersPharmacy.com.

EXTRA TIPS TO PREVENT DRYNESS

Breathing in steam from a hot shower…a hot, wet washcloth…or a hot cup of tea also helps, but those strategies won’t moisturize your nostrils as much as the techniques listed above.

Other ways to prevent dryness in your nasal passages and sinuses: Keep your home warm but not too warm (between 68°F and 72°F is generally best)…use a vaporizer or humidifier that’s easy to clean so you can keep it free of mold and bacteria (if you buy one that lets you set the humidity level, the Mayo Clinic recommends keeping it between 30% and 50%)…staying hydrated (drink extra water and cut back on caffeine and alcohol)…and, of course, not smoking, because that really dries you out.