Can You Get Sick From Cold Weather?

Cold temperatures are associated with colds, the flu, and runny noses, but cold air does not make you sick. If you find yourself getting sicker during the cooler months, this could be because of the lack of air humidity and the increase in indoor gatherings.

Being Sick From the Cold: What’s True?

A common misconception is that cold weather causes illness. In reality, it’s germs like bacteria and viruses that cause infections. This misconception tends to be due to the rise in influenza and other communicable respiratory infections in the colder months.

Research theorizes that the cooler months are related to an increase in illness for several reasons:

• Dryness weakens the body’s ability to defend against germs: Dry air during cold months decreases moisture on the skin and inside the nose and mouth. When the inside of the nose is dry, it limits the body’s ability to defend itself against intruding germs.
• Indoor gatherings increase contact with germs: People tend to gather inside to stay warm as the weather gets colder. Closer contact with more people inside increases contact with potentially infectious respiratory droplets from others.
• Lower vitamin D: Vitamin D is involved with immunity and is produced by UV radiation. Researchers theorize that during the colder months, when UV radiation is lower and vitamin D production is down, this could increase influenza epidemics.
• Respiratory droplets move farther and stay longer in the air: Cold air tends to be dry and low in humidity, allowing respiratory droplets to stay longer. When air is warm and humid, the moisture from the air causes the droplets to fall to the ground faster.
  

Exacerbated Conditions and Symptoms

Most people will recover from viral illnesses on their own within two weeks. However, people with chronic conditions or who are immunocompromised may develop serious symptoms.

Viral infections like influenza can cause serious complications like pneumonia from the influenza virus or an opportunistic infection from bacteria.

Other serious symptoms and infections caused by viral illnesses include:

• Encephalitis
• Myocarditis
• Myositis
• Sepsis

Viral infections can also make chronic conditions like asthma, diabetes, and chronic heart disease worse. People who are 65 years and older, pregnant, or young children are also at risk for serious complications.

How to Boost Immunity and Stay Warm

There is no one way to boost immunity, but there are several ways to help support the immune system and potentially prevent illness when it is cold outside.

One of the best ways to prevent certain illnesses is to get vaccines when available. The flu vaccine and pneumonia vaccine can help prevent infection and complications related to the condition.

Other ways to boost immunity include:

• Avoid smoking
• Eat a healthy diet
• Exercise regularly
• Lessen stress
• Maintain a healthy weight

Though many stores sell immune-boosting supplements and powders, research has not found that these supplements provide enough of an immune boost to prevent infection or disease. If someone feels that they are not getting enough nutrients in their diet, then a multivitamin or mineral supplement can provide benefits.

A Word From Verywell

Although we can’t prevent every cold or respiratory illness, we do have tools to prevent some of the most significant ones. Vaccinations are available for influenza, COVID, pneumococcal pneumonia, and RSV. Talk with your doctor to see which ones would be appropriate for you.

— JANE KIM, MD, MEDICAL EXPERT BOARD

Summary

When cold weather arrives, it brings along runny noses, colds, and the flu. But these illnesses are not caused by the cold. They are caused by an increase in gathering indoors and lower humidity. Make sure to wash your hands, cover your mouth when coughing and sneezing, and get the flu vaccine where available.