Youve got the idea just wrong order..with the probe on top of your substrate it is not measuring the temperature of the heat pad or the glass which could be much hotter than the substrate above. If the substrate moves or the snake Burrows the ssnake canget burned. You must put the probe between the glass and your heat mat. Then you use a lazer thermometer or a thermometer with a probe on the inside glass floor of the tank under the substrate, never on top of your Wood chips or whatever your substrate is. This is why your temperature is getting all screwed up, the probe is not measuring your heat Mats temp. Thats dangerous. The Thermostat/probe reading should always be within a couple degrees of what you have it set for.
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