It is installed in places that are exposed to one of the factors that do not allow the use of a smoke detector such as vapors and gases, which gives false alarms if smoke detectors are used. In addition to using heat detectors in places where a rapid fire can occur without heavy smoke. There are two types of heat detectors:

1- Constant temperature heat detector: It is used when the temperature of the place exceeds the temperature set by the device.

2- A heat detector that changes the amount of temperature during a specific period of time.) The two types are often used together (

Factors that affect the performance of the heat detector:

· High or very low room temperature

· Ceiling height, as it has been proven from statistics that the heat detector begins to sense the heat when the flame reaches a third of the distance between the fire site and the ceiling.