My Apple Watch is causing a burn mark and in 2022 it caused a pump on my wrist.

No point it wearing it for sleep tracking with heart sensor turned off.

Apple rarely find any fault with the watches reported to them.

• Wash your wrists night and morning.
• Moisturise at night.
• Use a damp facecloth to wash your watch back every night.
• Do not wear it at night.

If it persists, stop wearing it and see a doctor, and if they suspect nickel sensitivity consider either a barrier cream or the plastic backed SE watch 

My Apple Watch 8 has burned me twice now (while being worn overnight tracking sleep). I did a search and found something though I don't like this solution, but I think it will stop the burn.

I read in another thread that going into the watch app on your phone, then into privacy there is an on/off toggle for heart rate. In that thread it was suggested that turning this "off" only reduces the amount of tests the watch runs -- but from the way it's described in the watch app it looks like it disables heart rate tracking throughout the day though does allow you to still manually run tests.

I had the same sore spot and discontinued wearing the watch...I think it may be the nickel in the metal back. I bought the watch for the oxygen sensor. I could have bought an SE model. I move the watch back and forth after the wrist to help the skin heal.

We are not medical professionals here. Please see a doctor for diagnosis and any treatment needed.

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We want to make sure you reach the right team for help with your device. We recommend that you contact Apple Support directly. Depending on your region, you may be able to reach them here: Get Support.