With a dimmer your temp will always fluctuate unless you can get your room temp the same 24/7. Also fluctuations are going to cause stress. Your temp under the paper towel should never be higher than 94 bc of burns. Since your using paper towels I would keep it at 88 bc when your snakes weight is on the uth it will feel a couple of degrees warmer. If your on a budget your best bet is to get an Ink bird ITC-308 thermostat, they are a little less than $40 on amazon, this will automatically adjust temp when room temp changes so you won't need to monitor it constantly and can feel safe leaving home. If your have around $100 the Spyder Robotics Herpstat into + or Herpstat 1 would be your best choice since they have fail safes that will shut heat source off if it fails. I had a dimmer that failed and kept the heat source running on full power but luckily I was home and caught it before it killed one of my leopard geckos, I immediately switched to Herpstat and use them and VE thermostats for all my reptiles.

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