A burglar alarm or fire alarm device that detects a preset high temperature or a rapid rate-of-rise (ROR) in temperature. Heat detectors can be either electrical or mechanical in operation. The most common types are thermocouple and electro-pneumatic, both of which respond to changes in ambient temperature. If the ambient temperature rises above a predetermined threshold, then an alarm signal is triggered. Heat detectors are better than smoke detectors for areas where smoke would normally be found such as a kitchen or smoking lounge, since they do not produce as many false alarms.