Oh, and Louie...
Regarding your comment about heat rocks, the heat is concentrated towards the middle of the rock by design. The heat then permeates outward so the rock provides a gentle heat.
I haven't used a hot rock in a long time but used them for years & years and never had a problem with burnt reptiles. When the rocks failed, they got cold. Plus, because the heat flow was constant and gentle, there was never a need for a thermostat.
UTh's seemed to have caught on though and that's fine. IMO, they are much too hot and are more "Dangerous" than hot rocks to use. They really need to be used with a t-stat ($$) cannot be removed easily to be reused in other enclosures ($$) and make cage cleaning more difficult because you have to unplug them and drag the cord if you take the tank over to the sink or tub.
UTH's are a bit better for large snakes simply because they are available in large sizes.
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I last used a heat rock roughly 5 yrs ago and it was terrible . Threw it in garbage .
Granted like UTH several brands. Thus perhaps it was just one brand .
The UTH I love is COBRA . I havent turned them on since moving to Florida but when lived in NY used them roughly 9 months a year for 2 yrs and all worked great.
The insanely hot than cold type IMO is the zoo -med .
Another brand I threw away . One cracked my tank bottom.
COBRA you attach with scotch tape . Zoo med you can do same as don't have to stick it on but I wont go near those UTH pads ever again.
Cobra runs a steady warm temp doesnt go on and off like zoo med and never burns. I don't work for COBRA UTH lol but won't use zoo med again.
Now I just use slightly open blinds or open 1 or 2 ceiling ac vents in snake room depending on time of year as still 90 plus here during the day..