You should use a digital thermometer with a probe.(Walmart $12) Put the probe directly over the UTH (in the center) and under the substrate. It should be around 90F at the warmest spot. You will need a thermostat or rheostat to control the UTH output. It will be too hot without one (110-115F). If your room temp is pretty constant then a rheostat will work for now. You just need to keep an eye on it more than using a thermostat. You can order a temp gun pretty cheap nowadays. Proexotics.com has them starting at $15. They are a great way to measure temps throughout the enclosure. I use one for my BTS tank so I have it to use for the snakes too. Please check out the caresheets on this site as they are very good. If after reading them you still have questions feel free to ask. Not sure if you already have the snake or not. If you have not purchased yet then please make sure your temps are good before bringing him home. If you already have the snake you want to take care of the temp issue right away. Oh, and welcome to the site