I'm sorry. I have never heard of a dialog directing the user to shut down a particular app. That seems suspiciously weird to me. Can you grab and post a picture?
This happens when certain websites are using a lot of CPU. Not sure if it's the app itself or macOS but you will get a message saying that if you shut this page down, it will save energy.Can you take a screenshot of that message and post it here? I've never seen anything like this, and I'm almost 100% certain that neither macOS nor Firefox itself issue warnings like these.
Those I am familiar with. What I am not familiar with is the following:This happens when certain websites are using a lot of CPU. Not sure if it's the app itself or macOS but you will get a message saying that if you shut this page down, it will save energy.
A message keeps coming up saying to shut down Firefox to help cool the machine.
Like I said before this does not look like it's coming from either Firefox or macOS itself.
Do you have some sort of temperature monitoring software installed? Any tuneup tools that promise to make your system 150% faster for a nominal fee?