# Heating from underneath



## ekm5015 (Jul 27, 2010)

I have read on here that heating from underneath is bad. I am not saying that it is not, but I kind of question the reasoning and/or don't understand why. 

Why do many people say to place a flat rock under a heat lamp if heating from below is bad? The rock gets heated and the tort lays out on it. They are still being heated from the light on top of their shell, but they are also being warmed up from beneath. Those rocks can get pretty hot, much hotter than any heat mat would get. I have seen tons of wild turtles with no shell deformities laying on rocks to bask.

How hot does a heat mat really get...if the air temp is 70, placing a thin layer of substrate over the heat pad warms the substrate to about 80...why is that so bad?

I believe Sulcatta Stations is a reputable webpage with good info. They encourage the use of heating pads for their torts. All their torts seem healthy and undeformed.

Please no flames in this thread. Any arguments and/or facts that I'm missing are welcomed.


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## Yvonne G (Jul 27, 2010)

Here's my opinion...

A very young tortoise doesn't go out in the wild and find a hot rock to warm up on. They mostly stay in their burrow or under the bushes, hiding from predators. A very young tortoise captive doesn't realize that his "hot rock" or heating pad is getting too hot for him, and he may stay on it and suffer the consequences.

I'm in favor of using heat pads for larger tortoises. I've used pig blankets with my tortoises for many years and I've never had an accident or any deformed tortoises.

I also use a seedling heat mat under the outside of my baby habitats during the winter. A seedling mat doesn't get hotter than 80 degrees. I put the mat on the table, then place the plastic baby habitat tub on the mat, positioning the tub so the mat is under one end of the tub. Then I use at LEAST 4" of substrate, sometimes more. If the baby lays on top of the substrate, he feels hardly any warmth, but he does get the benefit of the heat rising and making the moisture in the substrate evaporate. If the baby digs down, even if he digs down to the floor of the tub, he'll only reach 80 degrees.


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## PeanutbuttER (Jul 27, 2010)

I think size also makes a big difference. Hot rocks are smaller than heat mats, and easier for the tort to put 2 and 2 together to realize how to get away from it when he/she's done. They can't see the heat mat, but they can see the hot rock. I don't think heat mats would really be all that bad to use if you knew how to use them and were careful not to cook your tort. I just prefer rocks in my enclosures because they seem to me like a more natural source of heat. It's actually something they'd come across in the wild.


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## Tom (Jul 27, 2010)

Here's where that all stems from. Back in the day 20 or 30 years ago the cheaply made "Hot Rocks" would short circuit or somehow malfunction and cook/burn reptiles. It wasn't IF it would happen, it was WHEN it would happen. The products are made to a much higher standard now, but back then those things would erupt into smoke and fire regularly.

Second thing is, many lizards have a third eye called a parietal eye. It is believed that this organ plays a large part in thermoregulation. Heat from below doesn't register on the parietal eye and so many lizards have gotten belly burns from staying on the heat pad for too long. Understand that it only has to be 110-120 for a burn to occur. The insulation provided by an animals body is enough to hold in the rising heat from a typical heat pad and create temperatures hot enough to burn.

Lastly, a flat basking rock isn't generating any heat. It immediately begins to cool as the animals body blocks the light from above and absorbs the heat from below. I never let mine get over 110-120 and within seconds of the animal covering the stone with its body, it begins to cool to safer levels.

Like you, I've been told that belly heat is a no no. I've been told that since the 80's. I know of at least one guy who is raising smooth leopards and belly heat is part of his strategy. It just needs to be done with the right equipment, closely watched and temps checked regularly. I intend to try this with my next batch of sulcata hatchlings.


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## ekm5015 (Jul 27, 2010)

Thanks for the responses. This wasn't as much of a debate as a learning session for me to understand more about heating from underneath. I think heating from below does have some benefits , although it definatley needs to be paid close attention to.


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## Yourlocalpoet (Jul 27, 2010)

Tom said:


> I know of at least one guy who is raising smooth leopards and belly heat is part of his strategy. It just needs to be done with the right equipment, closely watched and temps checked regularly. I intend to try this with my next batch of sulcata hatchlings.



Interesting that you should say that Tom, my Esmerelda has ALWAYS had a heat mat, in her viv when she was a baby and she still has one now in her warm hide, coincidently her favourite hide in the tort table. Never any problems as you've seen she has no deformities to speak of.


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## hpfirework (Jul 28, 2010)

I am so confused. In the wild, during the night, the air gets cooler than the ground (because of its greater heat capacity). The heat actually comes from underneath. I think using a heat mat in the night makes a lot sense than using a heat source hanging from above.


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## Tom (Jul 28, 2010)

hpfirework said:


> I am so confused. In the wild, during the night, the air gets cooler than the ground (because of its greater heat capacity). The heat actually comes from underneath. I think using a heat mat in the night makes a lot sense than using a heat source hanging from above.



Ambient heat dissipating from the ground after a hot day is totally different than GENERATING heat with electricity from underneath. The historical problem with belly heat has always been that its far too easy to get TOO MUCH heat. Kane heat mats for example are designed to hold 30 degrees above ambient. Great for a 40-60 degree CA night. The label, the product, the box AND the website all strongly tell you NOT to put anything on top of the mat. No bedding, no substrate, no blankets, etc. Craig, the owner of Kane Mfg., told me that there have been fires started because people put them under their couch cushions and other stupid things like that.

The other thing about overhead heat is that, for whatever reason, torts (and other reptiles) just seem to understand to get out from under it when they start getting to hot. For some reason they just sit there and burn on belly heat that gets too hot.


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## tortoisenerd (Jul 28, 2010)

For me, there are good alternatives to heat from above (ceramic heat emitters for example), so its something I'd never chance with a small tort. Sure there are ways to do it with a very low risk, but still more risk than a CHE in my opinion. Just not something I'm comfortable with, and I give advice based on what I'd do in the situation. I really agree with Yvonne's response!


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## Floof (Jul 28, 2010)

ekm5015 said:


> How hot does a heat mat really get...if the air temp is 70, placing a thin layer of substrate over the heat pad warms the substrate to about 80...why is that so bad?



The quoted statement above is dangerously inaccurate.

The average commercial heat pad/mat/under tank heater, whatever you want to call it, gets MUCH hotter than 80*F. Even those designed to stay on the cool side. In the interest of curiosity, I have, in the past, plugged UTHs directly into the wall, let them heat up for half an hour or so, then taken their temperatures with an infrared temp gun. My household usually runs a steady mid-60s in terms of temperature, and these tests are done before attaching the UTH to any enclosure, and without a layer of substrate (insulation) that might raise the temperature. Every single time, these heat pads have run in the range of 100 to 140 degrees... Most often on the high side.

So, actually, if you plug in a heat pad in a 70*F room and put it under a light layer of substrate, it will still get hot enough to seriously burn your reptile. The only real way to make sure these heat pads stay at a safe temperature is to get a good quality digital thermostat (i.e. my snake's beloved Herpstat, expensive but extremely reliable), and, even then, thermostats can fail.

On the subject itself, I can see some use in using a very low-wattage heat mat (on a thermostat set to a relatively low temperature, of course) under the enclosures of young and humidity-loving tortoises for the purposes of encouraging evaporation from the substrate.

Not so sure about using it as an actual heating element, though... Tortoises are diurnal animals, so designed to absorb their heat through light--the sun--and, to some extent, the sun-warmed land (which, as Tom has already mentioned, automatically begins to cool off when covered by the reptile in question's body). I use a heat pad for my snake because she is a nocturnal (maaaybe crepuscular) species that gathers that heat energy from the sun-warmed ground either from their burrow hiding places during the day, or when they come out to hunt after the sun has gone down. For terrestrial, crepuscular/nocturnal snakes (and other crepuscular/nocturnal reptiles, I suppose, though I don't have experience with them), a thermostatically controlled heat pad makes sense. And it works. And I don't have to blast my not-diurnal pet with otherwise unnecessary light. These factors don't exist in tortoise keeping. They need the light for their psychological well-being, anyway. So, why go so far as to use an alternative heating source such as a heat pad? To each their own, I guess, but it just makes sense, at least to me, to forgo the heat pad option when it comes to our diurnal tortoises/turtles.

I'll shut up now before I make myself sound like too much of an idiot. Still a novice with diurnal herps here...


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## ekm5015 (Jul 29, 2010)

Floof said:


> ekm5015 said:
> 
> 
> > How hot does a heat mat really get...if the air temp is 70, placing a thin layer of substrate over the heat pad warms the substrate to about 80...why is that so bad?
> ...



How is this "dangerously inaccurate"? I'm not talking about using a pig blanket in a small indoor enclosure. I'm talking about an 8 watt zoo med heat pad that you attach on the underside of a tank. It is designed to warm the air "2 to 8 degrees". By the way, the substrate actually insulates the tortoise from the heat rather than making it hotter.

This is what I did:
I placed some reptile carpet on the area where the pad was attached to the tank, and placed about 2 inches of substrate ontop of that. There is also a rheostat burried in the substrate to shut off the heat pad when it hits 85 degrees.

Bottom line is...I got blasted by a few people for "heating from underneath" and I just don't understand why this is so bad. Whether the heat comes from ontop or below, the tort still get warmed. There are obviously precautions to take when using a heat pad which I believe I took.


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## Floof (Jul 29, 2010)

ekm5015 said:


> How is this "dangerously inaccurate"? I'm not talking about using a pig blanket in a small indoor enclosure. I'm talking about an 8 watt zoo med heat pad that you attach on the underside of a tank. It is designed to warm the air "2 to 8 degrees". By the way, the substrate actually insulates the tortoise from the heat rather than making it hotter.



It's dangerously inaccurate because, as I mentioned before, they do not stay at 80 degrees without regulation. I wasn't talking about pig blankets, either--not sure where you got that idea.

I'm talking about those same ZooMed heat pads. I've tested ZooMed heat pads ranging from the smallest ones, rated for "plastic" enclosures, up to 30-40 gallon size (not sure of the wattages on them all, but since that smallest was the smallest they carry, I assume it's the same 8 watt you speak of). They all reached at least 140*F in a 65*F room. I would think, as a reptile keeper in any capacity, you would have come to realize that you can't trust everything the packaging says? ZooMed also says their "ReptiSand" products are a GREAT substrate choice and that the sand is completely digestible, and we all know that's extremely false.

On the note of insulation, the substrate only insulates the tortoise from the heat if the tortoise stays on top of the substrate, which we know tortoises do not do--they burrow. It's in their nature. As well, insulation works both ways. The substrate is holding the heat IN so it doesn't reach the tortoise or other animal full-force. Where do you think that heat energy goes? It stays right there, in the substrate layer. The heat pad continues to heat as the substrate retains that heat, effectively making the heat pad become MUCH hotter than it would otherwise. The more substrate, the more insulation, the hotter the heat pad.



ekm5015 said:


> This is what I did:
> I placed some reptile carpet on the area where the pad was attached to the tank, and placed about 2 inches of substrate ontop of that. There is also a rheostat burried in the substrate to shut off the heat pad when it hits 85 degrees.



First, you didn't mention the rheostat originally. How is anyone supposed to know you're talking about *regulated* heating pads when you don't say so? Second, where is the rheostat? On top of the reptile carpet? In the middle of the substrate? The only accurate measurement, and control, of temperature you can get is if it's as close to the heat pad as any animal in the enclosure can get--on the glass itself. Not as important with a tortoise who can't crawl under that reptile carpet, I realize, but still a fact.

Really, I suggest you do the experiment yourself. Ditch the substrate and the reptile carpet, plug the pad directly into the wall (no thermostat/rheostat/other control device), and, after an hour or so, take the temperature of the heat pad itself. Preferably with the more accurate temp gun, but if you don't have one, be prepared to leave the digital thermometer probe in place for 45 minutes or so to get an accurate reading. Once you've seen how hot your heat pad can get, maybe you'll understand what I was saying in my last post.



ekm5015 said:


> Bottom line is...I got blasted by a few people for "heating from underneath" and I just don't understand why this is so bad. Whether the heat comes from ontop or below, the tort still get warmed. There are obviously precautions to take when using a heat pad which I believe I took.



Are you using a heat lamp in conjunction with the heat pad? If no, this may explain why you got "blasted." Tortoises are diurnal animals. They need light for their psychological well-being. As well, they're designed to take in that heat from above. They aren't accustomed to having the land below them heat them, and, likewise, aren't designed to deal with it. This makes it MUCH easier for them to overheat or even get burned than if you were using a more natural overhead source.


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## Madkins007 (Jul 29, 2010)

Do they need 'belly heat'? Yes, to a limited extent. Most tortoises spend most of their day on a thermal mass so large (commonly called 'the Earth) that it will retain heat much of the night in the warmer months. By the same token, it will also remain mostly cool in the early months. 

They also like to digest at a moderately warm temp if possible.

IF your habitat's substrate is cool or clammy to the touch, I would argue that you would benefit from warming the soil from below- with the key word being WARMING. While cheapo heat mats may be unsafe or unreliable, things like decent quality greenhouse cables and Flexowatt strips are designed to not get over 80-90F, and can/should be run through a thermostat anyway. (By the way, I measured an unregulated Flexowatt at 90F)

Not only does this prevent cold tummys and toes, the warmth helps generate humidity out of the soil and if you are running a bioactive substrate, it helps keep it active in colder rooms.

Having said all that- if your room stays warm enough that there are no cold spots in the habitat, don't sweat it!


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## ekm5015 (Jul 30, 2010)

> It's dangerously inaccurate because, as I mentioned before, they do not stay at 80 degrees without regulation.



Ok...well as I go on to say, I am talking about regulation with a rheostat.



> First, you didn't mention the rheostat originally. How is anyone supposed to know you're talking about regulated heating pads when you don't say so?



Originally this debate was not about my setup specifically, it was on heating from underneath in general. I guess it has turned into me trying to figure out what exactly was wrong with my setup. People specifically told me what I did was wrong, knowing my setup. If there is something wrong, I don't see it. 



> Second, where is the rheostat?



I guess you began disecting my post before you read the entire thing. I stated that the rheostat is burried in the substrate. "Burried" may not be as specific as you are looking for, but if a tort is gona burry into the substrate, I think burrying the rheostat would take an accurate temp of where the tort would be. To be more specific, the rheostat is under the substrate, sitting on the reptile carpet.



> Are you using a heat lamp in conjunction with the heat pad? If no, this may explain why you got "blasted." Tortoises are diurnal animals.



I use a powersun, but it is not on at the same time the heat pad is on. When the light turns off at night, the heat pad comes on. I should have stated that this only comes on at night to keep the baby "warm" (80-85) not "hot" at night.

Thoughts?


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## Floof (Jul 30, 2010)

ekm5015 said:


> Ok...well as I go on to say, I am talking about regulation with a rheostat.
> 
> Originally this debate was not about my setup specifically, it was on heating from underneath in general. I guess it has turned into me trying to figure out what exactly was wrong with my setup. People specifically told me what I did was wrong, knowing my setup. If there is something wrong, I don't see it.



It seems we're having somewhat of a misunderstanding. What I mean is you didn't mention in the first post that you were talking about *regulated* heat pads. You said this...



> How hot does a heat mat really get...if the air temp is 70, placing a thin layer of substrate over the heat pad warms the substrate to about 80...why is that so bad?



No mention of a rheostat, thermostat, or any other regulation device. Everyone reading this post would be under the impression that all you're doing is putting a random commercial heat pad under the tortoise's enclosure, plugging it into the wall, and assuming it doesn't get hotter than 80 degrees. No regulation. No monitoring of the temperatures. No precautions to make sure that it really doesn't get hotter than that, or that it won't end up burning your tortoise.

Do you see now why I insisted on clarifying the dangers of unregulated heat pads? Why I was trying to get a better grasp of what you were talking about, using the example of your set up... Which, for the record, you're the one that brought up the subject of your personal set up, in response to my first post. 



> I use a powersun, but it is not on at the same time the heat pad is on. When the light turns off at night, the heat pad comes on. I should have stated that this only comes on at night to keep the baby "warm" (80-85) not "hot" at night.



See, this makes more sense, and even sounds like quite a practical idea for young, warmer-climate tortoises like your own.

Your first post was obscure, and didn't give those who may have agreed with how YOU do it a chance to understand. Simple mentions of temperature regulation and examples of using it at just certain points in the day may have helped this debate turn out more productive than it has, rather than giving readers the wrong impression from the start... But that's beside the point, now.

Hope I got my points across. Starting to hurt my own head... lol.


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## moswen (Jul 31, 2010)

i had a question something similar to this a few months ago only i am using a heated blanket that shuts off when it gets too hot and turns back on again when it needs to. i use it for my babies at night to help keep the humidity up, and i only put their enclosure on half of it so that they can choose to move away from it if they find it uncomfortable. i've found that sometimes they use the heated side, and sometimes they don't. i don't know what it depends on, maybe it's just where they end up when they're tired, but i haven't seen anything change for the worse or the better... 

i also have a trex uv bulb and a ceramic heat emitter placed in their enclosure, bc it's rather big. sometimes they choose to sleep under the ceramic heat emitter, sometimes they choose to bury under their substrate and sleep on the heated blanket side, sometimes they sleep in their hide, sometimes they sleep on top of or under the substrate where there is no heat blanket and it's cold and dry... but they've never all three slept together i've noticed that! so, here you have it i've been using it, seen no difference-bad or good, and my torts just sleep where they want to. i definately felt better about using it in the winter time bc i like to leave our house cold at night... 60 or 65 degrees. makes up for the cost of keeping it on 70 in the summer! but don't take my word for it, do your research and decide what you feel most comfortable with.

p.s., side note.... i bought a hot rock for my greek tula back before i "knew better" and before i joined this forum, and i actually still use it. i stopped using it like a year later when i found out "oh it'll burn your tort" but a couple months after that i decided it hadn't burned her yet, i believe if anything she preferred sitting on it, so i gave it back to her and i do believe she was excited, because for the next few days she used it every morning. there might be someone on here who thinks i shouldn't use it, but tula's happy and that's what i'm more concerned with!

so actually, all four of my torts have some sort of under belly heat emitter that they use when they want to!

some people have bad experiences and some have good, so just do your research, come to a conclusion based on your tort, your tort's circumstances, your tort's habitat, and your personal "comfort zone", and i'm sure you'll make the right decision! there's a lot more accurate information in books and on the internet now than there was 20 years ago, and a lot LESS... how shall we say... cheaply made nasty little reptile products... that chances are if the information you're getting is largely consistant from book to book or website to website then it's probably more accurate than say, cleaning a tort's wounds with a teabag (yes, read that online!)!!


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## Tom (Jul 31, 2010)

Rebekah, just remember that every hot rock worked perfectly right up until they day that it didn't.

My old one actually burned through the "rock" and was smoldering when I brought my turtle back in from his outside excursion. Seemed like divine intervention to me at the time.


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## moswen (Aug 2, 2010)

i totally agree with what you're saying tom, and I'm not saying this in a rude way at all, but every person's outdoor housing unit will work until the tort gets out...


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## Floof (Aug 2, 2010)

moswen said:


> i totally agree with what you're saying tom, and I'm not saying this in a rude way at all, but every person's outdoor housing unit will work until the tort gets out...



Very true, but a malfunctioning heat rock is a bit more deadly than a not-so-escape-proof outdoor enclosure.. 

If the heat rock works for you, that's great. I think Tom is just trying to warn you that if or when it fails, it will fail hard and can very potentially be the death of your tortoise if you aren't fortunate enough to have an amazing stroke of luck like Tom had with his experience.


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## moswen (Aug 3, 2010)

i can see that everything electrical has the potential to fail, but by my way of thinking, i think that tortoises are smart enough to get off a rock if it is causing them discomfort. just like they're smart enough to know what to eat in the wild if they're having a parasite overload, and they're smart enough to dig into the ground or under a shrub to escape the hot sun from above. i can see my ideas and beliefs on lots of subjects are different than the general vibe of most members of this website, but i do tend to hold to the idea that my prescious pets are able to reason themselves out of a dangerous situation! a hot rock that a tort can get off of is a little different than a heat lamp falling onto the tort and the little guy not being able to escape from underneath. 

this is just my opinion, not spoken rudely or with any hostility, just my thoughts on the subject! i hope everyone sees i'm not saying anything in anger, i just don't completely agree lol! that's why it's a debate!

and as a side note, i'm always hearing this can burn your tort, and no doubt there have been incidences of this happening or there wouldn't be that information circulating about, but does anyone have any real information on the subject? like "oh my tort was sitting on it and it burnt his plastron clean off..." or perhaps people were just keeping their pets in too small containers and the pets can't help but bump into a malfunctioned hot rock and burned their scales or shells? because i just honestly can't help but believe that an animal has enough common sense and instincts to... run from a fire, or move away from the heat, or eat when it's hungry or drink when it's thirsty... else i seriously doubt that species would still be around today haha!


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## Madkins007 (Aug 3, 2010)

That is one of the dangers of belly heat- many reptiles will press against a hot surface that causes significant, even life-threatening burns. I would not trust the animal to move in time.


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## Yvonne G (Aug 3, 2010)

moswen said:


> because i just honestly can't help but believe that an animal has enough common sense and instincts to... run from a fire, or move away from the heat, or eat when it's hungry or drink when it's thirsty... else i seriously doubt that species would still be around today haha!



But the trouble is, a very small tortoise, sitting on a heat pad, knows that is his whole life. He doesn't have the common sense or thought process to reason out the fact that if he moves a little to the left or right he will be able to move away from the heat. All he knows is he's sitting on something hot. His whole world's floor is hot.

I've even see very large sulcatas with burns on their carapace because the light was too close to the top of the shell. They don't understand that by moving to a different spot they can avoid the heat. They just know that there is heat. A tortoise's instinct isn't fight or flight. A tortoise's instinct is pull into your shell and play dead.

I'm pretty sure it was mentioned before. When a tortoise comes out to sit on a hot rock in the real world to warm up, once he covers the rock and makes shade on it, it starts to cool. An electric hot rock does not.


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## Floof (Aug 3, 2010)

Madkins007 said:


> That is one of the dangers of belly heat- many reptiles will press against a hot surface that causes significant, even life-threatening burns. I would not trust the animal to move in time.



Exactly.

I completely understand your reasoning, Rebekah, but the problem is, what if you're wrong? You can't predict 100% what your tortoise is going to do. It's the same reasoning behind the average keeper _not_ planting toxic plants in their tortoises' reach, or pulling up toxic plants when they appear. Sure, they usually do know to avoid the toxic and generally bad-for-them stuff, but you can't be sure they always will. So, why take the risk?

From what I have seen of uneducated reptile keepers' enclosures, where the most burns happen, the problem is often that the overheating hot rock or the unregulated heating pad is the only heat source. So, the snake/lizard/turtle/tortoise must choose between no heat at all, or way _too much_ heat.

Unfortunately, they often choose the latter. Both my female Russian tortoise and a ball python I once cared for were put in this situation before coming to me, and, despite being given enough room to move off their unregulated heating pads should they have wished, they both chose the heat. The ball python had the burn scars to prove it. Zoom's saving grace was that the heat pad was failing cold, to an extent, and seemed to be reaching only into the upper 90s/low 100s as opposed to the 140+ it had the potential to reach.


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