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

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 defenses.

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 defenses.

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.