Hi @Susie337
Installing a Wifi Thermostat is your best bet; especially in areas with extreme heat or cold. Doesn't seem like this will improve with climate change affecting everyone. Some Hosts I work with allow guests to adjust the temperature within a certain range (Host can control the range in the App). They usually allow between 68deg (F) - 73deg (F) as the range. This allows the guest to adjust within that range, without having to contact the Host constantly to do it.
We use the Emerson ST55 controlled by the Sensi App on your phone. $100 on Amazon or Home Depot. Not pricy but has all the bells & whistles you need in the Sensi App. You may need an HVAC person or Electrician to install it. The Emerson ST55 doesn't need a "C wire" to work, so that's why we use it:
Emerson Sensi ST55
https://sensi.copeland.com/en-us/products/wifi-thermostat
Those Hosts experiencing extreme heat right now should probably do as others have suggested and put a note in your Check-In Message about the thermostat and temps. With temps well over 100deg F, no way the temp can be cooled down to 65deg with most systems (especially in larger homes). Most heat pump and ductless systems can only reduce/increase temps by 20deg from outside temps (as others have pointed out). I probably would also put a small sign next to the thermostat to this effect as well. If you don't put a sign on the wall next to thermostat, you will get constanct complaints that the "AC isn't working."
Be sure not to set the temp too high when guests are not in the unit, as it can take a long time to cool down. In addition, with temps set high in the unit when no guests are there, the frig compressor has to work very hard to keep the temps cold inside. This will wear out your frig compressor much sooner. Most Hosts I work with set the temp at 73-75deg cooling when no guests are there. Then the morning of guest check-in they set the temp to 71-72deg.
