A gradient that runs from top to bottom
A panther chameleon lives in a tall, screened enclosure, and its temperature gradient runs vertically rather than end to end. At the top, on a horizontal branch positioned under the basking lamp, the surface should reach roughly eighty-five to ninety degrees Fahrenheit. Through the middle of the cage the ambient air should sit in the mid seventies to low eighties, and the lowest, most thickly planted zone should rest in the low seventies, shaded and still. After the lights go out the whole cage should fall into the sixties or low seventies. That night drop is not a failure of heating; panther chameleons come from highland-influenced Madagascan forest where nights cool noticeably, and the drop supports normal rest and appetite.
Setting the basking branch, not just the bulb
The number that matters is the temperature on the branch where the chameleon actually sits, measured at the height of its back, because a chameleon's body rides above the branch and closer to the lamp than the wood itself. Fix the basking branch a safe distance below the bulb, then fine-tune by moving the branch up or down in small steps rather than swapping bulbs repeatedly. A hand held at casque height under the lamp should feel warm, never hot; if you would pull your hand away, the chameleon's back is too close. Adult males generally use the top of the basking range. Females and juveniles should be set nearer eighty-five degrees, since overheating a female adds strain her body does not need, and a youngster on too hot a branch can burn before it thinks to move.
The cool zone and the foliage that makes it
The lower cage only stays cool if it is genuinely shaded. Dense live or silk planting in the bottom half breaks up the lamp's reach and gives the chameleon a place to disappear into the low seventies without leaving its territory. That retreat is where the animal goes after feeding, on warm afternoons, and whenever it wants to feel hidden, which for a chameleon is much of the day. Screen sides help the whole system work: moving air prevents the stagnant, evenly hot box that a glass tank can become under a strong lamp. If the lower zone reads the same as the middle, the lamp is too powerful for the cage or the planting is too thin, and the chameleon has effectively lost half of its gradient.
Water, humidity, and their effect on temperature
Panther chameleons drink from droplets on leaves, and the misting or dripper routine that provides those droplets also cools the foliage and lifts humidity, which should sit moderately through the day and rise overnight. Run misting sessions in the morning and late afternoon rather than at midday under the full heat of the lamp, and let the cage dry somewhat between sessions so it does not stay permanently sodden. A chameleon that sits gaping under the lamp is too hot, not thirsty in the ordinary sense, and the fix is a gradient correction or a cooler room, not more water sprayed into hot air. Persistent gaping, sunken eyes, or a chameleon that stops feeding for days calls for a reptile veterinarian rather than further lamp adjustments.
Checking a setup that changes with the seasons
Room temperature swings move the whole gradient up or down, so a setup perfect in spring can run hot by midsummer. Recheck the basking branch and the lower zone whenever the room's weather changes, and after any bulb replacement. If the numbers still look off before the lamp is finally positioned, put a follow-up question to KinsLe's Kinny; he answers using the KinsLe Answers library.