@MDK what you would need to do is employ some sort of micro controller. For example, Arduino is a platform that has a huge online repository of code and tons of people to answer questions. ESP32 is another good one. Raspberry Pi would work as well. Bottom line is you need something with GPIO pins to interact with the real world.
You would need to have a bluetooth radio on the microcontroller.
You would write the software to communicate with the sensorpush and read the reply and react. So in pseudocode
(On microcontroller)
Initialize Bluetooth Comms
set bt receiver address (sensorpush device)
Send read byte
listen
grab response, assign to variable
Call processing subroutine
Sleep for X minutes and check again
Processing Sub()
Compare new reading with last reading
Is stable? - quit sub
Is different?
compare new value to set value
Is temp higher than set value? Yes = turn on exhaust fan
bla bla bla
To turn on a fan for example, you would take something like this
and wire the GPIO pin to the IN1 pin on the relay board. When you set the GPIO pin to LOW at the microcontroller, the relay turns on supplying AC to the blower.
Then continue to monitor the bluetooth, and when it gets too cold, shut it off.
It is actually a lot easier than you might think, and pretty damn cheap if you are handy. You could do the whole thing for $20.