A company that uses internet-connected thermometers to predict the spread of the flu is tracking the coronavirus in real time — something that had been impossible, given the lack of testing for the disease. Kinsa Health has sold or given away more than a million smart thermometers to households in which two million people reside, and can record fevers almost as soon as consumers experience them. For the last few years, Kinsa’s interactive maps have accurately predicted the spread of flu around the US about two weeks before the CDC's own surveillance tool, the weekly FluView tracker. The most common symptoms of infection with the coronavirus is a fever and just last Saturday, Kinsa’s data indicated an unusual rise in fevers in South Florida, even though it was not known to be a Covid-19 epicenter. Within days, testing showed that South Florida had indeed become an epicenter.