Megg hit on some of the important points. It's important to differentiate between hot spot and ambient temps. Ambient readings measure the temperature of the air within the enclosure. It is important to keep these within the mid 70s to the low 80s. The hot spot temp on the warm side is the temperature that the snake will experience on the floor of the enclosure. This temperature should be anywhere in the high 80s to low 90s. This temperature needs to be taken with an infrared heat gun. These can be purchased online or at a big box hardware store.