As summer comes to a close, another season takes its place. Hot, muggy days are replaced with the cool, crisp air of fall. But fall brings more than relief from the heat. Fall signals the start of cold and flu season, leading many people to get sick more than any other time of year.

There’s a definite link between cold weather and catching a cold. While fall increases the spread of germs, it’s still possible to make it through the cold months without contracting a viral infection. Check out the top ways to strengthen your immune system heading into fall.

Why is fall considered cold and flu season?

Many people believe cold weather can make a person sick. This isn’t entirely true. Cold weather isn’t a direct cause of the flu or common cold. Bacteria and viruses cause people to become ill, not a drop in temperature. However, cold temperatures can weaken the immune system, which makes you more susceptible to getting sick.

Fall is considered cold and flu season because respiratory viruses spread more easily in cold, dry air. Viruses are transmitted via droplets that spread when an infected person coughs or sneezes. Lower temperatures and humidity levels can increase the distance viruses travel through the air. One study also concluded that cells exposed to cold temperatures have a suppressed immune response.

Cold weather can affect the immune system in other ways, too. When you breathe cold air, blood vessels narrow in the upper respiratory tract to contain heat within the body. Narrow blood vessels decrease the flow of white blood cells to the lungs, which makes it harder to fight off infections.

Staying indoors also increases your risk of getting sick. People spend more time inside during fall and winter to avoid the cold weather. Viruses spread more easily in confined areas because people are interacting within close proximity to each other. Staying inside more often also decreases sun exposure, which can lower your vitamin D levels. Vitamin D is crucial for a healthy immune system, so absorbing less of it may result in more cases of the flu or colds.

Tips to strengthen your immune system

Cold weather can take its toll on your immune system. Fall signals the start of cold and flu season, but that doesn’t mean you’re guaranteed to get sick. People with a strong immune system can easily make it through the cold months without contracting an infection.

Follow these tips to build immunity before the temperatures drop.

• Improve sleep quality: The immune system is closely tied to your duration and quality of sleep. Adults who regularly get seven hours or more every night tend to have a stronger immune system. The body needs adequate rest to fight off viruses and bacteria before they develop into true illnesses. Quality sleep is equally important, so create an environment that will help you fall and stay asleep. Avoid screens an hour before bed, sleep in a dark room and lower the thermostat at night.
• Make time for moderate exercise: Regular physical activity offers many health benefits, and it’s especially known for boosting the immune system. Moderate exercises such as hiking, cycling and swimming reduce chronic inflammation and assist with immune cell regeneration. While inflammation is a normal immune response, sustained high levels of inflammation can actually make it more difficult to fight off pathogens. Reduce your chances of getting sick this fall by engaging in moderate activity three times a week.
• Eat probiotic-rich foods: A majority of the immune cells reside in the gut. With that in mind, it comes as no surprise that boosting gut health can strengthen the immune system. You can support healthy digestion by eating more probiotic foods. Probiotics are live cultures filled with beneficial bacteria that limit the amount of pathogens in your digestive tract. The good bacteria fight infection by helping immune cells identify the differences between normal bodily cells and harmful pathogens. Great sources of probiotics include yogurt, kefir, kimchi and sauerkraut.
• Take an immunity supplement: Supplements are a quick and easy way to strengthen your immune system all year round. Taking a daily immunity supplement can improve your body’s response to stress, which is one of the biggest culprits behind a weak immune system. Reishi and turkey tail mushrooms possess adaptogenic properties, meaning they calm stress’s impact on the body. Other ingredients like elderberry, cat’s claw and astragalus root have been long regarded for their immunomodulating effects.

When the temperatures drop, more people will start to come down with a cold. You’re likely to cross paths with many who are carrying a respiratory virus. Strengthen your body’s natural defenses to ward off sickness and stay healthy as we head into the coming fall season.