A high-temperature thermostat is a device that prevents the temperature from exceeding a predetermined limit in the monitored environment, usually as a safety feature. For example, the high-temperature thermostat on many dryers turns off the heating element if the temperature inside the unit exceeds 240 degrees Fahrenheit.
Standard thermostats, like those associated with home heating, are designed to keep the temperature at or near the set point, cycling the heating between on and off. High-temperature thermostats are designed for use in environments where the heat remains on for the majority of the time and only intervene to turn off the heat when it exceeds the safety limit. This usually happens due to a malfunction, such as clogged ventilation, elsewhere in the system.