Can you get ill from being cold?
Put simply, cold weather alone doesn’t make you ill. However, it can increase your chances of becoming ill. This is partly why illnesses such as colds and flu (influenza) are more common in winter months. To understand why this happens, it helps to think about viruses, which cause these illnesses.
What viruses cause respiratory illnesses?
Colds, flu, and COVID-19 are respiratory illnesses that are caused by different viruses.
- More than 200 viruses can cause the common cold. About half of all colds are thought to be caused by rhinoviruses.
- Three types of influenza virus (influenza A, B, and C) cause flu.
- COVID-19 is caused by a virus called SARS-CoV-2.
You can catch a cold, flu or COVID-19 if you come into contact with one of these viruses, often from someone else who’s already infected.
If you catch a cold, you might find you have a mild temperature, sore throat, blocked or runny nose, and are sneezing or coughing. If you get the flu, your symptoms are likely to be more severe. As well as the symptoms of a cold, you might also have a headache, fever, chills and feel aches and pains. You will also need to stay in bed for a few days. Symptoms of COVID-19 can vary from person to person, but many are similar to cold and flu symptoms. For some people, however, COVID-19 can be more severe than flu.
Why are viral illnesses more common in the winter?
Here are some of the reasons why more of us get viral illnesses in the winter.
We spend more time together indoors
When it’s cold outside, we stay warm indoors more often. But being in close contact with one another during the winter months means viruses can spread more easily from person to person. Viruses can move through the air in droplets when you sneeze or cough. It is spread by hands or may live on contaminated surfaces like door handles. This means that crowded or enclosed spaces, such as public transport, schools and the workplace, are the perfect breeding ground for viruses.
Some viruses thrive in winter conditions
Research has found that some of the viruses responsible for colds and flu can survive more easily in cold, dry conditions with little sunlight. Droplets that contain influenza viruses (for example, from coughing and sneezing) can also stay in the air for longer if it’s dry.
Your body’s defences may weaken when it’s cold
Your immune system protects you from disease. Some early studies have suggested that the cold and dry conditions of winter could make it harder for your immune system to fight off viruses.
Your nose and airways are lined with mucus and tiny, hair-like structures called cilia. They act as a barrier by trapping viruses that you breathe in and moving them out of your airways. Your mucus also contains antimicrobial substances that help to protect you from disease. But breathing in cold, dry air during the winter months can affect the mucus and cilia lining your nose and throat, making them less efficient.
So, if you do come into contact with a virus during the winter months, your body’s defence mechanisms may not be as good at fighting it off if you’re cold. This is especially true as we grow older because our immune systems become weaker with age.
Four tips to stay healthy in winter
More research is needed before we can fully understand the relationship between the cold weather and respiratory illnesses. But for now, there are some things you can do to help keep yourself healthy during the winter months.
- Adopt good hygiene. You can help prevent the spread of winter bugs by practising good hygiene. Cover your hands and mouth with a tissue when you cough or sneeze and put the tissue in the bin straightaway. Wash your hands thoroughly with soap and warm water and regularly disinfect surfaces. And avoid touching your eyes, nose or mouth until you’ve washed your hands, in case they carry any germs. If you have visitors, try to ventilate rooms before they arrive and for at least 10 minutes after you leave the room.
- Get vaccinated. You can reduce your risk of getting flu and COVID-19 if you’re vaccinated against them. It’s important to have the flu vaccine each year, as it changes annually to try and match the dominant type (strain) of virus for that year.
- Practise healthy habits. Living a healthy lifestyle supports your immune system and helps fight off any germs you might come into contact with. Try to eat a healthy diet, get enough sleep, exercise regularly and don’t smoke.
- Consider taking a vitamin D supplement. Your body makes most of its vitamin D from sunlight. Vitamin D is also found in oily fish, eggs, meat and fortified breakfast cereals. But during the winter months, the lack of sunlight makes it difficult for your body to make the vitamin D it needs. And not getting enough vitamin D can make your immune system more susceptible to infection. In the UK, it’s recommended that all adults and children older than one should consider taking a daily supplement of 10 micrograms of vitamin D during autumn and winter.