The Collaborative International Dictionary of English v.0.48:
Telethermometer \Tel`e*ther*mom"e*ter\, n. [Gr. ? far off + E. thermometer.] (Physics) An apparatus for determining the temperature of a distant point, as by a thermoelectric circuit or otherwise. [1913 Webster]WordNet (r) 3.0 (2006):
telethermometer n 1: a thermometer that registers the temperature at some distant point