This isn't a question that already doesn't have an answer. Researchers showed at the Common Cold Centre in London that body temperature has an impact on the lik

This isn't a question that already doesn't have an answer. Researchers showed at the Common Cold Centre in London that body temperature has an impact on the likelihood of catching flu. The reasoning is that during the cold, less blood flows to the extremities to maintain core body temperature. This includes less blood flow to the nose. Flu lives in the nose, and white blood cells are what attacks flu, so having less blood in the nose means less white blood cells which means less chance of killing the virus off before it takes hold.