Chances are, when you’re burrowed under the covers with a box of tissues by your bedside, you turn even greener with envy thinking of those people who seem to never get sick. Want to be one of them?

While colds won’t kill you, they can weaken your immune system to the point that other, more serious, germs can take hold in your body. Just think how many times your cold turned into bronchitis or a sinus infection. And given that the average adult suffers two to three colds a year, that’s a lot of opportunities for serious illness — and just as many to prevent one!

1. Wash your hands and wash them often. The Naval Health Research Center conducted a study of 40,000 recruits who were ordered to wash their hands five times a day. The recruits cut their incidence of respiratory illnesses by 45 percent.

2. Use this hand-drying strategy in public restrooms. Studies find a shockingly large percentage of people fail to wash their hands after using a public restroom. And every single one of them touches the door handle on the way out. So after washing your hands, use a paper towel to turn off the faucet. Use another paper towel to dry your hands, then open the door with that paper towel as a barrier between you and the handle. It sounds nuts, but it’s an actual recommendation from the Centers for Disease Control to protect you from infectious diseases like cold and flu.

3. Carry hand sanitizer with you. Colds are typically passed not from coughing or kissing (although those are two modes of transmission) but from hand-to-hand or hand-to-object contact, since most cold viruses can live for hours on objects. You then put your hand in or near your mouth or nose, and voilà! You’re sick. Carry hand sanitizer gel or sanitizing towelettes with you and you can clean your hands anytime, even if the closest water supply is 100 miles away. It works. One study of absenteeism due to infection in elementary schools found schools using the gel sanitizer had absentee rates from infection nearly 20 percent lower than those using other hand-cleaning methods.

4. Use your knuckle to rub your eyes. It’s less likely to be contaminated with viruses than your fingertip. This is particularly important given that the eye provides a perfect entry point for germs, and the average person rubs his eyes or nose or scratches his face 20-50 times a day, notes Jordan Rubin, Ph.D., author of the book The Maker’s Diet.

5. Stop blaming yourself when things go wrong at work. Believe it or not, blaming yourself makes you more likely to catch a cold! At least, that’s what researchers found when they studied more than 200 workers over three months. Even those who had control over their work were more likely to begin sneezing if they lacked confidence or tended to blame themselves when things went wrong. Researchers expect such attitudes make people more stressed on the job, and stress, as you know, can challenge your immune system.

6. Put a box of tissues wherever people sit.Come October, buy a 6- or 12-pack of tissue boxes and strategically place them around the house, your workplace, your car. Don’t let aesthetics thwart you. You need tissues widely available so that anyone who has to cough or sneeze or blow his nose will do so in the way least likely to spread germs.

7. Take a garlic supplement every day. When 146 volunteers received either one garlic supplement a day or a placebo for 12 weeks between November and February, those taking the garlic were not only less likely to get a cold, but if they did catch one, their symptoms were less intense and they recovered faster.

8. Eat a container of yogurt every day. A study from the University of California-Davis found that people who ate one cup of yogurt — whether live culture or pasteurized — had 25 percent fewer colds than non-yogurt eaters. Start your yogurt eating in the summer to build up your immunity before cold and flu season starts.

9. Once a day, sit in a quiet, dim room, close your eyes, and focus on one word. You’re meditating, a proven way to reduce stress. And stress, studies find, increases your susceptibility to colds. In fact, stressed people have up to twice the number of colds as non-stressed people.

10. Scrub under your fingernails every night. They’re a great hiding place for germs.

11. Change or wash your hand towels every three or four days during cold and flu season. When you wash them, use hot water in order to kill the germs.

12. At the very first hint of a cold, launch the following preventive blitz. Here’s how:

* Suck on a zinc lozenge until it melts away. Then suck another every two waking hours. Or use a zinc-based nasal spray such as Zicam.

* Take one 250-milligram capsule of the herb astragalus twice a day until you are better.

* Cook up a pot of chicken soup.

* Roast garlic in the oven (drizzle whole clove with olive oil, wrap in tinfoil, roast for an hour at 400°F), then spread the soft garlic on toast and eat.

Studies find that all either reduce the length of time you suffer with a cold or help prevent a full-blown cold from occurring.

13. Wipe your nose — don’t blow. Your cold won’t hang around as long, according to a University of Virginia study. Turns out that the force of blowing not only sends the gunk out of your nose into a tissue, but propels some back into your sinuses. And, in case you’re curious, they discovered this using dye and X rays. If you need to blow, blow gently, and blow one nostril at a time.

14. Sneeze and cough into your arm or a tissue. Whoever taught us to cover our mouths when we cough or sneeze got it wrong. That just puts the germs right on our hands, where you can spread them to objects — and other people. Instead, hold the crook of your elbow over your mouth and nose when you sneeze or cough if a tissue isn’t handy. It’s pretty rare that you shake someone’s elbow or scratch your eye with an elbow, after all.

15. Don’t pressure your doctor for antibiotics. Colds and flu (along with most common infections) are caused by viruses, so antibiotics — designed to kill bacteria — won’t do a thing. They can hurt, however, by killing off the friendly bacteria that are part of our immune defences. If you’ve used antibiotics a lot lately, consider a course of probiotics — replacement troops for friendly bacteria.