Each year, when sniffling, sneezing, and fatigue shift into high gear, many of us rely on old-school remedies or even folklore to prevent or treat colds and flu.

As soon as you clear your throat or pull out a tissue the advice starts rolling in, from chicken soup to Echinacea and homespun cough remedies.

But do any of them really work?

To help you navigate cold and flu season, we asked internal medicine physician Dr. Vivian Lin to separate fact from fiction for 10 common cold and flu beliefs.

Read: Can You Really Boost Your Immune System?

1. The flu shot causes the flu
Fiction. "The flu shot is not a live virus, so you can't get the flu from the vaccine," says Dr. Lin. "But that's not to say you can't catch a cold or even a flu after you get vaccinated." It takes a week or two to get protection from the vaccine.

Plus, the vaccine usually contains 4 strains of the inactivated virus, so there's always a chance you can get infected with a different strain. Nevertheless, the flu shot is still your best defense during flu season.

2. Being cold can bring on a cold
Fiction. There's no evidence to suggest being cold increases your risk of getting a viral infection. Instead, people tend to get viruses when the weather turns colder because they spend most of their time indoors in cramped quarters where germs can readily spread.

3. Air travel can make you sick
Fact. Being trapped inside a confined space for several hours with a lot of people increases your risk of catching a cold or flu. After all, if the passenger next to you is coughing, you're stuck inhaling their virus. Low humidity in pressurized cabins may also be a likely cause.

4. You're only contagious if you have a fever
Fiction. "When you catch a cold or flu, the virus is in your system before you feel sick," says Dr. Lin.

"So even if you have no symptoms, you can still spread the flu."

You're most contagious during the day or two before you notice symptoms and for a few days after you begin feeling ill.

Read: Am I Still Contagious? 

5. Feed a cold, starve a fever and vice versa
Fiction. Whether you have a cold or a flu, you should eat healthful foods. When you're fighting a virus, your body needs energy and nutrients to bolster your immune system.

"Fluids are more important than food though," says Dr. Lin. Water, tea, soup, and broth are all good choices.

6. Honey helps relieve a cough
Fact. The natural sweetener's antimicrobial and antioxidant properties can help squash an infection. And when you have a hacking cough, adding honey to warm liquid, whether water or tea, can help coat the throat and ease the pain.

Leading health organizations, including the World Health Organization, recommend honey as a cough suppressant. But go easy. Honey is loaded with sugar and calories—and you can't give it to children who are less than a year old since it may contain spore-forming bacteria that can lead to botulism.

7. Chicken soup can help ease cold/flu symptoms
Fact, sort of. Chicken soup is full of immune-boosting ingredients such as carrots, celery, onions, and garlic. But chicken soup itself isn't a cure-all.

While a handful of scientific studies show that chicken soup could have medicinal value, most of the research on the matter is inconclusive. But sipping soup of any sort can help you stay hydrated and soothe a sore throat.

Read: Honey and Your Health

8. Supplements can help you speed through the flu
Fiction. Studies on supplements ranging from Echinacea to zinc have come back inconclusive.

In fact, some supplements, such as zinc, can harm you. "Zinc comes with a lot of gastrointestinal side effects, and it can interact with certain medications," says Dr. Lin.

Vitamin C is a big immune system booster but it's better to get it from foods (citrus, spinach, broccoli) than out of a bottle.

9. Antibiotics can treat the flu
Fiction. Antibiotics treat bacterial infections, not viruses, so they're not effective against a cold or flu.

Here's the twist: "Some people develop a secondary sinus or bacterial infection as a complication of the flu," explains Dr. Lin. If you have persistent high fevers or your symptoms worsen, see your physician to determine whether antibiotics can help.

10. It is too late to get vaccinated after Thanksgiving
Fiction. Vaccination can still be beneficial as long as flu viruses are out there. Flu is unpredictable, and seasons can vary. Seasonal flu usually peaks between December and March, but you can catch it as late as May.

"The best time to get the vaccine is October or November before peak season hits," says Dr. Lin, "but it can still be protective to get vaccinated in December or later."

Read: When Should I Take Antibiotics?

There are a number of ways to protect yourself against cold and flu. The best line of defense:

• Get vaccinated
• Wash your hands
• Stay hydrated

Still sick despite these precautions? Most viruses clear up without any medical attention or intervention.

But if you're concerned, see your doctor at the first sign of illness to determine whether anti-viral medication is right for you. And if you choose to go with over-the-counter cold and flu remedies, talk to your doctor first.

"Certain over-the-counter supplements and medications may even be dangerous, particularly when combined with prescription medications," says Dr. Lin.