It's sick season. Here's how to protect yourself from norovirus, COVID-19, flu and RSV

Dr. Kalina on preventing illness Dr. Dale Kalina explains the cause of rising cases of viruses across the country and how to prevent contracting illnesses during flu season.

In the winter months, it seems few are safe from some kind of illness — flu, COVID-19, norovirus, colds.

While many of the germs that cause this misery can circulate throughout the year, scientists think that the winter surge of flu and cold activity may be because we spend more time indoors and the cold, dry air may weaken our defences.

But knowing what these bugs are and how they spread can help. While it may be difficult to make it through the season totally unscathed, there are some things you can do to protect yourself from these respiratory and stomach viruses.

How do I know whether I have the cold, the flu, COVID-19 or something else?

Some symptoms are hard to distinguish among illnesses, especially with respiratory viruses. Others are unmistakable.

— Norovirus is a foodborne illness that can spread through water and contaminated surfaces and can cause vomiting, diarrhea, nausea and stomach pain for about one to three days.

— The common cold can be caused by several different types of viruses and can cause a runny nose, congestion, cough, sneezing, sore throat, headaches, body aches or low fever for less than a week.

— The flu, caused by influenza viruses that are always changing, leads to fever, chills, cough, sore throat, runny nose, body aches, headaches and feeling tired. Flu symptoms tend to hit more quickly than cold symptoms, and can last anywhere from a few days to two weeks.

— COVID-19 can cause fever, chills, cough, short of breath, sore throat, congestion, loss of smell or taste, fatigue, aches, headache, nausea, or vomiting for several days.

— RSV can cause a runny nose, congestion, coughing, sneezing, wheezing, fever and a loss of appetite for a week or two.

One way to protect yourself from all viruses: Wash your hands

Seriously. Rigorous and frequent handwashing — with soap! — is crucial to reduce the spread of norovirus, colds, flu and COVID-19.

This is especially true after using the bathroom and eating or preparing food, the U.S. Centers for Disease Control and Prevention says.

Don't speed through it, either. Count to 20, slowly, while you scrub away.

If you don't have access to soap and water, try a hand sanitizer with at least 60 per cent alcohol — though that isn't enough to wipe out norovirus.

Cleaning surfaces can wipe out viruses

If norovirus has found you, you'll want to immediately clean surfaces that came in contact with contaminated food or bodily fluids. The CDC recommends disinfecting things with a chlorine bleach solution or one of the products listed on this Environmental Protection Agency website.

Don't forget to wash any clothing that came in contact with vomit or feces — use hot water and detergent. Then, wash your hands. Again.

With colds and flu, it's best to regularly clean surfaces that you come into a lot of contact with. Think doorknobs, light switches, countertops, beloved toys, cellphones.

Use household cleaning products that contain soap or detergent, and follow it up with a sanitizer. The CDC has more tips on how to clean.

COVID-19 generally spreads through the air from droplets and particles, and the CDC says the risk of getting the virus from a contaminated surface is low.

Keeping your hands off your face can keep viruses out

Viruses can spread through talking, coughing and sneezing, so cover your mouth with a tissue if you feel a tickle in your throat or your nose. Then, wash your hands. Again.

Also, even if you're not sick, consider masking in crowded areas with an N95 or medical-grade mask to protect yourself from respiratory viruses.

Don't touch your face: If you have a germ or virus on your unwashed hands — respiratory or norovirus — and touch your face, eyes or nose, it can get into your mucus membranes and, voila!, you're sick!

Consider a vaccine (if there is one)

Updated COVID-19 vaccines are available, as well as annual flu shots for people 6 months and older. For those 60 and older or for people who are pregnant, you may want to get the RSV vaccine.

But there is no vaccine for norovirus or the common cold.

Another way to keep your defences against viruses up: Rest

Your immune system may not work as well if you're sleep-deprived, stressed out or dehydrated. So don't grind yourself into the ground if you can help it. Rest. Sleep. Drink water.

If you are sick, stay at home

If you do get sick, prompt testing can help determine whether you have COVID-19 or influenza. That’s important to see if you need one of the medicines that can help prevent severe illness: Paxlovid for COVID-19 and Tamiflu for flu.

Above all, if you're symptomatic, stay at home to keep from getting others sick.

To treat a cold, flu or COVID-19, rest and drink fluids. You can take pain relievers to lower a fever or help with an achy body. Humidifiers can help with symptoms, too.

There's no medication for norovirus. Instead, you'll need to rehydrate as much as possible with water and other liquids. Seek help if you are dehydrated and notice you have a dry mouth and throat, aren't urinating as much or feel dizzy when you're standing up.

AP Medical Writer Carla K. Johnson contributed to this report.

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group and the Robert Wood Johnson Foundation. The AP is solely responsible for all content.