If you are using any heat near the substrate of a PFD enclosure, may I respectively suggest getting aquarium type thermometers; stick them in the soil in more than one spot! 78F should absolutely be the the cut off ( the
warning zone) They could die in a prolonged temp > 80F .
I use the one in the far right in this photo.
Hagen Thermometers
I use heat cables ( exo terra) in the winter only ( on timers ) as my tanks are in the basement.
These need to used w/
extreme caution. I do not have them touching the glass.
I believe you can purchase thermostats
Lynn