The Nest Thermostat is a threat is equipped with a smoke detector. And you can set it to where it will turn the air conditioning down by itself. Which is good becuase it will not be running when you are gone so it will not be burning fossil fuels when you are not using it and it will reduce your air conditioning bills and heating bills.
The Nest thermostat is a round thermostat that is equipped with not only a thermometer but with an smoke detector it will also tell you if something is wrong at your house like if the air conditioning turned up or down r if water pipes burst. The Nest also is a clock and will show the time when you walk into the room where the Nest is in.