The flu season has arrived - and it's weeks early.
In one week, 16 states and New York City reported high levels of the flu. By the following week, that number was up to 29.
Each day for the past week, more than 500 New Yorkers have descended on emergency rooms with flu symptoms, according to a city website.
According to the Centers for Disease Control and Prevention, in high flu states 70 percent to 80 percent of the coughs you hear around you right now stem from the flu.
Each cough, sneeze or even conversation puts the virus into the air - and potentially into your lungs.
The virus goes everywhere - onto railings and the salt shakers in the diner; on the keys of the ATM; and on every door anyone touches.
The flu virus can survive two to eight hours on hard surfaces such as metal and plastic - touch it and you can spread it to your nose and mouth from your hand.
The average person touches his or her face about 18 times an hour - giving the virus a path to the lungs.
In one meeting, ABC News recorded the number of times people unconsciously touched their faces in more than 25 minutes. The highest number of times: 44.
There are now new tools to track the flu.
The CDC is watching social media flu sites such as Google Flu Tracker, and a Facebook app tries to identify the "friend" that gave you the flu from its searches and comments.
Flunearyou.org has 20,000 volunteers who are tracking their symptoms, narrowing the spread of flu down to your ZIP code.
An office hot spot? The elevator. One sneeze can spray the flu - in droplets - up to 20 feet, coating the doors and buttons. And what do you touch in an elevator? The buttons.
The CDC suggests washing your hands and getting a flu shot - still available and effective within two weeks.
If you get sick, cover your cough and sneeze with your elbow, not your hand so you are less likely to spread the virus.
Those at high risk for severe disease - young children, seniors, pregnant women, those with medical problems - should see their doctor. Antiviral drugs might prevent your illness from getting worse.