In the hard winter months we bundle up and stay indoors more often. We rarely air out our homes, although we should do this even when it is cold outside. These are just a couple of the reasons why we’re more likely to get sick in winter – germs thrive best in closed spaces. There’s another reason why we get sick more in winter that you may not have thought about, and it has to do with the kind of long-term, often subtle illnesses that result from exposure to indoor pollutants. Winter is the time of year when our body burden can increase the most.