One of the most important chameleon killer factors in their husbandry is OVERHEATING.
Chameleons are very sensitive to react to temperatures which are above their ideal temperature span but surprisingly they relatively well tolerate temperatures which are a little or even significantly lower. So, for example the feral populations of the panther chameleon in the vicinity of Orlando easily tolerate for two months almost daily drops of temperatures near the freezing point while in the home country they are very rarely exposed to drops under 10°C.
If we overheat chameleons heavily, they die almost immediately but if we overheat slowly slowly, they can fool us with their ability to hide even the indicators of sickness and tolerate it for short time and die after few weeks or even months. If we overheat the chameleons long-term, we speed up their metabolism and significantly shorten their lifespan.
Why are temperatures so important? Well few examples:
1. Without cool phase, males can not produce sperm
2. With too high temperatures, females lay too many eggs and die often because being egg bound or even just exhausted
3. With too high nighttime temperatures, they can not sleep and rest, thus get exhausted, ill and die...
Bur what are the root causes that we so willingly overheat our chameleons?
1. We trust wrong authors and care sheets. It is sometimes ridiculous how many terrible mistakes authors of care sheets make and what unbelievable inaccuracies or even lies they write there. Trust info from reputable sources only!
2. We believe, if animals come from near equator, they need it hot! Chameleons very often live at high altitudes, where it is rather cold. So, Trioceros rudis, ntunte, schubotzi, kinangopensis: they all survive daily drops to freezing point! T. hoehnelii can eat at temps below 5'C! And at daytime, it gets rarely above 18/20'C! The skies are cloudy and sun is scarce!
3. We do not pay attention to climatic data from the country of origin: very rarely people search for climate data - it is soo easy! I Iphone, it takes yiu about 5 seconds to get the climate of almost any city on the planet Earth! Same in internet! It is not necessary to ask people in SM, just google! The trick is, google the RIGHT PLACES, not any. Google places where they live, not the capitals. So, when you for example google Aden in Yemen and apply the temperatures from there. You kill the animals as they live 3000-7500m higher in the mountains around Ibb and Yarim in a totally different climatic zone!
4. We wrongly interprete even the right climatic data... We need to understand, most climatic stations are situated IN the cities, where temperatures are easily 5-7 degrees above the temps in the biotopes outside and even nighttime temperatures due to accumulation of energy in buildings and roads are higher by some degrees! Moreover, the chameleons sit most of the time in shade in bushes and trees, the temperature is there about 3-7 degrees lower than in shade outside and can be 20(or more) less than on a sun. So, the basic temperature should be as a rule of thumb 7-10 degrees lower than the ambient temperature shown in the climate charts. Unless you have biotope data, that is a different story. But we are smart and offer to Veileds basking spots over 35'C: a temperature, which is never reached in their home-country!
5. We do not pay attention to night drop. People often ignore a night drop and think a "room temperature is enough". It is NOT enough! How can be a Veiled chameleon comfortable when in his country, in March as example, the night temps fall to 7-10 degrees Celsius, if we cook them at night at 25?! Or even 20?! They can not sleep well, they get exhausted, their metabolism speeds up and they die at half of the age they could live.
6. We do not understand their basking behavior. This a thing that almost no-one understands, even some great breeders would swear the opposite. Chameleons do not live in areas, where all the day - there is sun! On contrary, very often, the sun is quite limited to several minutes or tens of minutes per day! It is absolutely true for the montane species but also for Madagascan including panther chameleons. The breeders say then: they have to know how much they get and they can regulate themselves! The truth is, in many to most cases They have no clue!!! Their program is: whenever there is sun, let us catch some IR rays to warm up! And in the wild, they get their several minutes and then a cloud comes. But what we do?! We offer them a basking light full day!!! They overheat and die! They can not not-apply their strategy they learned for millions of years. So, they bask until death! It is not a fairy tale, it is reality. Most T. hoehnelii and jacksonii die in the captivity exactly because of this. Most aborts and deaths of young are due to this!
7. We assume the animals have already adapted to the life in EU and US. They adapted to their environments for millions of years, few years and few generations in captivity make absolutely NO difference.
We misunderstand and interprete the thermal conditions and believe it is good enough
BUT, it is lethal for chameleons or at least it causes a heavy discomfort, leading to early death...
Some people say: "I live in an area, or in a house or flat, where I can not simulate the proper temperatures."
The ultimate answer is, sorry for my french:
Either you find a way or abscond from keeping chameleons. They will suffer and die.
So, What to do?
Act responsibly and keep your chameleons cool, based on real research, not on parroted wrong information!