Why do hot rocks burn, and heat pads not (as much)

[hungba]

Why is it that there are so many burns from heat rocks? What is it about them specifically? Heat pads/tape etc. even when outside under the tanks also heats the floor so that the animal touches the heated (as vs ambient heat). The heat also comes from below instead of above, so that "no heat sensors on belly" thing doesn't explain it. Nor does heat trapped under the reptile as both heat rocks and pads are underneath. Substrate makes a difference but some people use newspaper for snakes and tile for dragons etc.

Is it just because people don't use a thermostat?

I want to build a heated shed for large lizards for winter sleeping out of plywood and heat mats/tape/cable underneath it. I see people build these with pig blankets for large tortoises. I just want to know what it is about hot rocks that causes burns so I do not "duplicate" that fault in my diy projects.

[bcr229]

I believe it's because, like you said, people tend not to use thermostats with hot rocks.

For large torts or lizards look at a Kane heat mat for heat - they're designed to take the weight and abuse from livestock such as pigs, so they're great for large snakes and lizards.

[Albert Clark]

Forget the plywood! Wood is the number 1 attractant for mites and their eggs! Try pvc or plastics. Good luck. Any other material except wood.

[Stewart_Reptiles]

While you can use a t-stat with heat tape trying to secure a t-stat to a rock without it dislodging itself would be impossible, therefore they are use unregulated.

[hungba]

So it is simply the fact that no t stat, not because anything inherrent about them because they are in the form on a rock?

Reasons given by lizard people usually are that reptiles don't feel heat on their bellies and don't know it is hot, but snake guys use UTHs. Also something about "hot spots" on the rock. Doesn't really add up.

[Zincubus]

While you can use a t-stat with heat tape trying to secure a t-stat to a rock without it dislodging itself would be impossible

Glue gun ?

[Eric Alan]

So it is simply the fact that no t stat, not because anything inherrent about them because they are in the form on a rock?

Pretty much this. Both products are meant to create a heated surface for a reptile to rest on top of. The key difference is that the rock is intended for use inside of the enclosure, making it much more complicated to temperature regulate properly.

Reasons given by lizard people usually are that reptiles don't feel heat on their bellies and don't know it is hot, but snake guys use UTHs. Also something about "hot spots" on the rock. Doesn't really add up.

If you think about how heat transfers in nature, it will help clear things up for how burns happen in captivity. If a reptile lays on a warm surface in nature, their bodies absorb heat while the surface loses it. The surface itself typically doesn't generate it's own heat, so reptiles didn't have a need to develop the nerve endings to be able to sense these temperature changes that seemingly defy nature. In captivity, our heat surfaces don't lose the heat they are transferring to our reptiles. Thus, if the surface is on the hot side, it will continue to be on the hot side regardless of how long the reptile stays put. That's why it is so important to be able to regulate this kind of heat inside of your reptile's enclosure.

In regards to the rock's "hot spots", they are side-effect of the heating element used and the shape of the rock itself around that element. UTHs, whole not perfectly even 100% of the time, do not have the inherent design flaws that add to the temperature inconsistencies.

[Stewart_Reptiles]

Reasons given by lizard people usually are that reptiles don't feel heat on their bellies and don't know it is hot, but snake guys use UTHs.

This is true for some species including BP (which is why they often get burned) however it applies regardless of the heat source used if not controlled. T-stat allow temp control, prevent overheating which lead to burns and most importantly lack of T-stat can be a serious fire hazard.

Glue gun ?

Sooner or later especially since the glue will warm up it will dislodge itself not worth the risk when there are supply out there that are safe when used properly.

[kitedemon]

A number of things here. The old style hot racks used to get stupid hot, and were prone to go crazy and become biblically hot. They also used to fail regularly, I would assume that the encapsulated heat element is to blame perhaps. This became so common the product has been viewed with extreme distrust. They claim they are improved. But the issues still remain, attaching the probe in such a way it is firmly fixed and not prone to external influence. The failure rate seems to be fairly high to this day as well. These combine to make it undesirable at best. Add the small surface area and the radiant nature and thermal blocking that could happen while an animal lays on it you get yet another possible of disaster.

The snakes not feeling heat is silly, they do. Scientists have used heat stimulus to measure snakes responses for years. The current idea of why a snake will not move off a overly hot heat source comes down to physiology.

Snakes have a large lung (and depending on species a small one too) The lung passes heart, liver and much of the arteries. The air it contains influences the core temp of the snake. Larger snakes cannot regulate the core temps completely from the outside. When the air temp is too low the snake will stay on the heat source in an attempt to raise the core temp. They seem to choose life over limb and take the burn rather than die.

This idea has not been proved but thought to be accurate by vets like Dr. Mader, and Klingenberg.

This also explains why snake get burns on the sides and back as well.

(there are also contact burns where a surface is so hot that it burns on contact i.e. the point where if you touch it you get burned too not a durational burn that only seems to happen with captive reptiles)

[Eric Alan]

The snakes not feeling heat is silly, they do. Scientists have used heat stimulus to measure snakes responses for years. The current idea of why a snake will not move off a overly hot heat source comes down to physiology.

Has Dr. Mader published updated information since this article that I am familiar with?

Relevant passage from his Understanding thermal burns in reptile patients (Proceedings):

Why then, when a reptile rests on such a "hot" hot rock, don't they also immediately jump off?

Nobody seems to have an easy answer for that. It is not uncommon for a snake to wrap its coils around a bare light bulb because it is attracted to the warmth that the light emits. So, it must feel the warmth, why then, does it not feel the burning heat?

One answer is that the nerve receptors that sense heat and the receptors that sense pain are different. It is possible that, since in the wild, such pain receptors have no evolutionary significance (reptiles do not come into contact with intensely hot objects in the wild). Therefore, evolutionarily, there is no reason that a reptile should have a hot-pain withdrawal reflex.

Other theories put forth suggest that since reptiles do not reason in the same fashion that people do, or other mammals for that matter, even though they may feel pain, they do not associate it with the object that they are touching. Hence, they do not realize that they need to move in order for the pain to subside.

Bottom line is, nobody really knows. So, until we understand why these animals are so prone to burns, the best thing to do is make every effort to prevent the burns in the first place.