If you’re wondering where illness is spreading in the US right now, the official CDC flu map might not be particularly helpful; it’s based on data that’s both delayed and not very local.

Instead, try this new map that uses anonymous data from smart thermometers. When someone gets a fever, the data helps build a detailed picture of who’s sick.

 “The sad fact is, we have almost zero accurate information about where and when disease is starting or spreading,” said Inder Singh, CEO of Kinsa. “It’s all based on models that are pretty inaccurate.”

Other models use data including the sale of cold medicine–which comes with a delay, since people may have been sick for a few days before going to a pharmacy–or medical records, which are delayed even more, and don’t track the length of an illness. (Google Flu Trends, which tried to predict the spread of flu based on Google searches, shut down after missing the peak of the 2013 flu season.)

Kinsa realized that technology could help gather better individual data, and decided to gather it through thermometers since that wouldn’t involve changing behavior. “We said, let’s give people a smarter, cheaper, better version of a product that they already use within hours of symptom onset,” Singh says.