From your cold winter example I wouldn’t be using several IOT devices, just the one.
For projects that have multiple IOT devices I would probably put each one on a separate TAB (Android now allows lots of TABS). Each IOT device sends an ID and an incrementing number at say 3 second intervals.
So Garage-0003, Garage-0004, Kitchen-0008, Kitchen-0009, Bedroom-0015, Bedroom-0016.
If the numbers are not increasing or looping back to zero I know the data from these devices is stale.