The first thing people should probably do when they fear they have contracted the novel coronavirus is call their doctor. The first thing most people actually do is Google their symptoms.

That’s good news for researchers. Google is sharing its treasure trove of data about runny noses and fevers to help health researchers learn more about covid-19, the disease caused by the coronavirus. The data set could even help them predict future hot spots for the disease or learn more about what long-term effects it has.

On Wednesday, Google is making county-level data on symptom searches in the United States available to researchers and the public. The information goes back three years and includes up to 400 symptoms and conditions, not just those known to be associated with covid-19. It will have information on searches for things such as stress and diabetes so experts can learn more about secondary health impacts.