Smartwatches were once laughed at as gimmicky, unnecessary add-ons to the already complete smartphone experience. Now though, research coming out of Stanford University suggests that some of these wearables could help you predict when you’ll fall ill.

Michael Snyder of that particular university was conducting a study on the reliability of their readings when he noticed that they were all showing that his heart beat rate and skin temperature were increasing while his blood oxygen levels dropped. He began treating himself for Lyme disease in response to other indicators and sure enough, the diagnosis was right on the money.

“Once these wearables collect enough data to know what your normal baseline readings are, they can get very good at sensing when something’s amiss,” he said. “We think that if your heart rate and skin temperature are elevated for about 2 hours, there’s a strong chance you’re getting sick.”

Smartwatches with fitness trackers could even be a more accurate indicator of health than annual health checks as they show you fluctuations within your own normal rate rather than the normal rate of the average member of society.