1) Cryostat 2) Pyrostat 3) Thermostat 
• (n.) A device for the automatic regulation of temperature; a thermostat.
Synonym for thermostat ... <physics> A self-acting apparatus for regulating temperature by the unequal expansion of different metals, liquids, or gases by heat, as in opening or closing the damper of a stove, or the like, as the heat becomes greater or less than is desired. ... Origin: Thermo- + Gr. To make to stand. ... Source: Websters Dict...
Ther`mo·reg'u·la`tor noun (Physics) A device for the automatic regulation of temperature; a thermostat. 
Type: Term Pronunciation: ther′mō-reg′yū-lā′tŏr, -tōr Synonyms: thermostat
thermoregulation, thermoregulator 1. Temperature control, as by a thermostat; heat regulation. 2. The regulation and control of temperature, specifically internal body temperature. 3. The various physiological processes by which the body regulates its internal temperature. The process by which an organism regulates its internal body temperature ...thermoregulator A highly accurate and sensitive thermostat.