Apple spilled the beans on a bunch of cool new stuff for Apple Watches at their big developer conference this year, including a brand new app called Vitals. This app is supposed to be a game-changer for health nerds, letting you track all sorts of health stuff and take control of your well-being. Pretty neat, right?

Here’s the catch though, and it might mess with your sleep routine. To get the most out of Vitals, Apple says you gotta wear your watch to bed. Big bummer if you’re used to leaving your watch charging while you snooze.

According to Apple’s health honcho, Dr. Sumbul Desai, wearing your watch at night lets Vitals get a clearer picture of your health. Things like your heart rate and body temperature can be affected by your daily activities, so nighttime readings give the app a better baseline. Think of it like a health snapshot based on your sleep.

Vitals won’t just throw a random health score at you. Instead, it compares your current readings to your usual numbers. If a couple of things seem way off, Vitals will give you tips to get yourself back on track. But don’t worry, it won’t freak you out and tell you to run to the doctor every time something’s a bit different. They only want to nudge you when there’s a real issue.

Apple Watches already track sleep to some extent, but watchOS 11 (the new software) is supposed to be even better. Vitals could really put Apple in the game with some of those fancy sleep trackers out there.