How big is the enclosure? How big is the water dish? What wattage is the bulb? Sounds like the bulb is too hot, or the dish is too small. I have great luck with a ten gallon tank, a heat pad, and a 40 watt bulb. Always between 50 and 60%. Also do you have a thermostat? If not, move the substrate and place your hand directly on the bottom of the tank right over the heat pad. If you can't hold your hand there you have a dangerous situation for your snake.