Sensor Card, How can I set a permanent line/reference to a specific temperature?

[drowsy sonnet]

I have a RTL sensor to check my refrigerator temperature. It's kind of difficult to see overall sometimes since it moves around a lot, so I was wondering if there is a way to set like a permanent line at the 40F mark for easy reference? Similar to how the picture looks.

[viral parcel]

I don't think you can do this in the standard card
Apexchart-card can do it, you can add a second series to be your horizontal line

You could also use the color threshold option to just change the colour above/below the value you care about - though that's an experimental feature