You want to know who’s researching the flu on Google? The search engine giant can tell you. Google has developed a tool to track searches for the flu to predict hot zones of flu activity.

Google Flu Trends was the product of Google.org, the philanthropic arm of the Internet giant, according to The New York Times. It analyzes millions of everyday Internet searches and isolates key words, such as “flu symptoms,” “sore throat” or “influenza.” Google Flu Trends then creates charts and maps showing where those searches are taking place. Because people tend to research their symptoms before contacting a doctor, Google Flu Trends can predict a widespread outbreak of disease up to 10 days before the Centers for Disease Control and Prevention is alerted by area physicians, reports the Times.

To develop the new flu tracker, researchers at Google.org compared five years of search results for specific keywords with CDC maps of influenza outbreaks. While the correlation between the two data sets was very strong, some in the healthcare field would like to analyze Google’s processes more scientifically. The journal Nature is expected to publish a paper on the Internet search engine’s methodology, according to the Times.