ther·mo·sta·ble 
(thûr′mō-stābəl) also ther·mo·sta·bile (-bəl, -bīl′)
(thûr′mō-stābəl) also ther·mo·sta·bile (-bəl, -bīl′)adj.
Maintaining structural and functional properties when heated, as an enzyme or toxin.
ther′mo·sta·bili·ty (-stə-bĭlĭ-tē) n.