Temperature Switch

A temperature switch is one detecting the temperature of an object or Atmosphere at times. Temperature switches often use bimetallic strips as the pressure-sensing element, the motion of which actuates one or more contacts(which can be a switch).
The “normal” status of a switch is the condition of minimum stimulus. A temperature switch will be in its “normal” status when it senses minimum temperature

If the trip setting of a temperature switch is below ambient temperature, then it will be “actuated” at ambient temperature and in its “normal” status only when the temperature falls below that trip point (i.e. colder than ambient).