We brrrreak it down: This is why you're more likely to catch a cold in winter

Winter is well known as the "cold and flu season", but do you ever wonder why it's more common to catch a cold or the flu during the colder months?

There are many theories as to why we're more susceptible to respiratory viruses in the winter, and these include the ability of germs to thrive in colder weather, people being in close proximity more often, and, more recently, scientists discovering that the cold air in winter may damage the immune response in the nasal passage, leading to higher risk of falling ill. 

Theory 1: Weakened immune response