The present invention discloses a thermostat (1) of the type having a thermal probe comprising a hollow tube (3) of thermally expansive material having a first coefficient of expansion within which there is provided, fixed thereto at the distal end thereof, a rod (11) of substantially thermally non-reactive material such that when heated a linear displacement between the rod (11) and the tube (3) is utilized to actuate a regulating switch. The thermostat (1) comprises a probe assembly having a base plate (7) to which the tube (3) of the thermal probe is fixed and a switching assembly (5) securable to the base plate (7) and includes a cover element (9). The thermal probe also houses a sensor (45, 47) filled with a thermally expansive fluid in communication with a diaphragm (15) fixed to the base plate (7) and operable to actuate a movement amplifying switch actuator to provide a safety over-temperature cut-out function. The thermal interruption and safety cut-out mechanisms are wholly independent. The present invention also discloses a method of assembling a thermostat (1) which includes the steps of fixing a hollow tube (3) of thermal probe to a base plate (7) having attached thereto mounting points for a movement amplifying switch actuator, forming the thermal probe by positioning within the hollow tube (3) thereof a rod (11) and a fluid-filled sensor (45, 47) disposed adjacent or about the rod (11), mounting the switching assembly (5) to the base plate (7), and testing the temperature points at which thermostatic interruption and over-temperature cut-out functions operate.