If it's under 60 out, I wear a hat. Doesn't matter if I'm going from my car to a building 30 seconds away. Those 30 seconds add up. Sometimes don't even bother with the coat, always wear the hat though. I get maybe 1 cold every 5 years, usually having to do with not bothering with my hat. Never get the flu. Just saying, prevention is the best remedy. And oh yeah, people who say wearing a hat has nothing to do with catching a cold or flu do not know what they're talking about.