Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ex-calfăcĭo, no perf., factum, 3, v. a., to warm, to heat (post-Aug.; esp. freq. in Pliny the Elder): excalfacit, Plin. 21, 20, 82, § 139; 21, 21, 89, § 155: excalfieri, id. 24, 7, 28, § 42; Scrib. Comp. 158: lacus sole excalfactus, Plin. 37, 2, 11, § 37; 37, 10, 54, § 148: ad excalfaciendos nervos, id. 21, 22, 93, § 163.