The temperature doesn't have anything do do with the flu, or the common cold. Just a myth there.
Well, there is a connection, but not what you think.
When it gets cold, people stay inside more, and thus people are closer together. Easier for disease to spread.
Please take this outbreak of flu VERY seriously. A strain of flu back in 1918 killed the most people in the fastest time, ever.
Yes, more deadly than the plague, ebola, AIDS, or any other disease in history.
It's not likely to be any where near as bad this year, but it will kill many people. Please be careful and get your flu vaccine if you can.