Florida hot weather is like not other place on the planet.
That said there are now many choices of electronic devices where you can visually check and/or be alerted of a temperature change.
This will only work IF you are 'close' enough to get back to your RV before they expire from the heat. And hope that you have consistent coverage where you have gone to 24 7's to receive the alert.
An RV is a non insulated box sitting and baking in the sun nothing more.
I have been in my MH when the power went out in the blazing Florida heat. Opening windows and turning 12v fans did absolutely NOTHING to relive the mounting heat inside an RV. The temp goes from 80 to well over 100 inside an RV in literally seconds. The only relief is getting OUT of the RV until power is restored.
Relying on a thermostatically controlled fantastic fan will drain your battery faster than you can say expired pets. And the fan would have to be the model that 'opens' the lid. Not all have this option.
I do NOT leave pets in the MH unattended when in Florida. It's just way too dangerous. Just saying.