If you have a camera with specific hardware and a particular software revision, you might experience a bug with the temperature scale not being persistent between reboots. To solve this, make sure that the camera has the latest firmware, and then go to http://<Camera IP>/prod/res/image/settings/initial/active?set=true.
If the problem has been solved, you will see a page that looks like this:
Next, reboot the camera, which should now function as intended.
If any problems arise, don't hesitate to contact our support agents,