A burrower's thermostat problem
The pacman frog spends its life half-buried in the substrate, eyes at soil level, waiting for prey to wander within reach of its enormous mouth. It regulates its body temperature the way burrowers do — by moving: deeper to cool off, shallower and toward warmth to heat up. That instinct is exactly why the standard under-tank heat mat is dangerous for this species. A frog that feels too warm digs down to escape the heat, and a mat under the glass puts the hottest spot in the enclosure precisely where a cooling frog settles. Burns and chronic, invisible overheating are the well-known results.
Heat from the side or above
Build the warmth horizontally instead. Mount a heat mat on the outside of one end wall of the enclosure, or fit a low-power ceramic heat emitter or deep-heat lamp above one end, in a guarded fitting the frog can never touch. Either arrangement creates the gradient this frog actually uses: a warm end in the mid-eighties and a cool end in the mid-seventies, with the frog commuting between them through the day. Night can drift a few degrees cooler, which mirrors the frog's home ground and needs no special equipment in most homes.
A thermostat is not optional
Whatever source you choose, it runs through a thermostat — dimming or pulse type — with the probe positioned at substrate level where the frog actually sits, not dangling in the air measuring a temperature the frog never experiences. Fit two digital thermometers, one at each end, so that a single failing reading shows itself against its twin. Check both daily. An unregulated mat or emitter can run far hotter than the glass or the air suggests, and a pacman frog cannot call out, scratch at the glass or move house when its one warm corner quietly becomes an oven.
Moisture is half the system
Heat cannot be judged apart from water in a frog enclosure. The substrate should be deep enough for the frog to bury itself to its eyes, and kept damp throughout — moist, never swampy — with misting to hold humidity steady against the drying effect of the heat source. Provide a large, shallow water dish the frog can climb into and sit in. Read the frog as an instrument, too: one that parks permanently in its water dish is very often telling you the substrate or the air has become too hot or too dry, and the thermometer readings should be checked before anything else is changed.
What never belongs in the tank
Heat rocks are the classic trap — a burrowing frog presses its belly against them and burns. Unguarded bulbs within the frog's reach belong on the same banned list. And beware the setup with no cool end at all, where the whole floor is uniformly warm: a frog without a cooler retreat has no thermostat of its own, and no way to tell you it is slowly cooking. Because a pacman frog cannot tell you the gradient has drifted, KinsLe's Care Teams keeps the twice-daily thermometer checks on a shared rota — a missed check shows up, and your frog's warmth never depends on one person's memory.