Once the weather turns colder, it feels like everyone is sneezing, sniffling, coughing, shivering, and potentially getting you sick.

While it might seem inevitable that you will fall prey to that most common of colds, there are some very natural, effective ways to keep illness at bay.

First, try discerning whether you have a simple (yet, still irritating) cold, or the much more serious influenza virus.

Colds rarely cause fevers, and the symptoms come on slowly, usually starting with a sore throat and leading to a stuffy, runny nose that lingers for a few days. The flu, by contrast, tends to hit people like a truck, with a fever, sore throat, headache, congestion and cough coming on quickly, and often all at once.

Click here to read more cold and flu stories.

Americans catch nearly 1 billion colds each year, and between five and 20 percent of people in this country will contract the flu, but there are steps you can take to keep your immune system up to snuff:

• Wash hands frequently with a non-toxic soap that is free of ammonia, dyes, phenols, phosphates, sulfates and artificial fragrances. Also keep hand sanitizers within reach at all times, but make sure to buy one without Triclosan, an additive that has been shown to alter hormone regulation in animals.

• Feel a sneeze coming on? Wrap your arm around your face, and sneeze into your elbow. This way the germs don’t wind up on your hand, where they’re much more likely to come in contact with other people.

• Get your Vitamin D3 levels checked! Around three-quarters of Americans—from the elderly to newborns—are deficient in Vitamin D3, which has been linked to the health of nearly every organ in the body, as well as the immune system. Once you determine your levels, figure out how much supplement you need to achieve the optimal amount of Vitamin D3 in your body.

• Eat plenty of fresh, organic leafy greens (like kale, chard, and broccoli) and cruciferous vegetables (like cauliflower, radishes, and cabbage). They’re good for you every day of the year, but their high vitamin C content comes in especially handy during cold and flu season.

• Increase your intake of fermented foods like sauerkraut, miso, and sugar-free strained Greek yogurt, which boost your overall wellness by promoting intestinal health. Acting as probiotics (which can also be taken as supplements to keep the stomach flu away), fermented foods aid digestion, improve immune function, and up vitamin B levels, all key in warding off sickness.

• Exercise! Keeping your heart rate up has been shown to help the body fight simple infections like colds and flu.

• Sleep well and as often as possible. Studies indicate that people who get less than seven hours of sleep per night are three times more likely than their well-rested counterparts to contract the common cold.
If you’ve already succumbed to a bug, there are many homeopathic, common sense remedies that’ll get you back on your feet quicker than you can say, “Achoo!” Some of my favorite tonics include:

• Use a Neti pot, which irrigates stuffed nasal passages with water.

• Making a nutritious vegetable broth with shitake mushrooms, miso paste, onions, garlic, turmeric, cayenne pepper and olive oil.

• Diffusing therapeutic-grade, 100 percent essential oils—like clove, cinnamon bark, eucalyptus, or rosemary—throughout the home can make breathing easier. Also, using the oils during a steamy shower can provide relief to clogged sinuses.

• Finally, drink copious amounts of pure, filtered water all winter long. People tend to under-hydrate when the weather turns cold, leaving them more vulnerable to infection and less capable of fighting something off once they’ve got it.

The dark, snowy days of winter will come and go, but your health is forever—make it a priority in all seasons.

Deirdre Imus is the founder and president of The Deirdre Imus Environmental Health Center™ at Hackensack University Medical Center and Co-Founder/Director of the Imus Cattle Ranch for Kids with Cancer. She is a New York Times best-selling author and a frequent contributor to FoxNewsHealth.com, Fox Business Channel and Fox News Channel. Check out her website at dienviro.com. 'Like' her Facebook page here.