Where is the hotel temperature sensor installed?

Smoke and temperature are in 90% buildings, and the white circle installed under the ceiling is a smoke alarm probe. When the surrounding smoke or dust reaches a certain concentration, the red indicator light on the circle lights up to show the signal in fire detection.

Under the ceilings of kitchens, garages and some places, white round objects are temperature-sensitive alarm probes. When the temperature changes more than 15 degrees Celsius, the red light will be on, which is the same as the smoke alarm process.