"through, by means of," 1580s (earlier in various Latin and French phrases, in the latter often par), from Latin per "through, during, by means of, on account of, as in," from PIE root *per- (1) "forward," hence "through, in front of, before, first, chief, toward, near, around, against."
1590s, "burning, glowing, hot," from Latin fervidus "glowing, burning; vehement, fervid," from fervere "to boil, glow" (from PIE root *bhreu- "to boil, bubble, effervesce, burn"). Figurative sense of "impassioned" is from 1650s. Related: Fervidly; fervidness.
<a href="https://www.etymonline.com/word/perfervid">Etymology of perfervid by etymonline</a>
Harper, D. (n.d.). Etymology of perfervid. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/perfervid