First of all, congrats on the frog! I'm glad it's a fantasy frog. Never heard of a Petco or PetSmart carrying fantasies before, very interesting. It's a very pretty frog. As for the temperature question, pacman frogs love to burrow, and spend a lot of time almost invisible. However, the best temp for pacman frogs is usually recommended to be around 82-83. Sometimes slight differences are recommended for the various species, however. For measurement of the temperature, depending on where you place your thermometer(s), you may be fine; for example, if the heating pad is off to the right and the thermometer is in the middle or to the left, it may be a bit hotter on the area near the pad than the thermometer shows.