You have two options
1# Keep the room temp at 85/86 and you won't need supplemental heat
2# Have your ambient temp at 76/78 and provide a PROPER hot spot at 86/88 how does not matter some ways are more efficient and more cost effective with less heat loss UTH for example, however is has to be regulated with a RELIABLE thermostat, if you set your thermostat properly outside the enclosure right on the heat pad your temps should not be 104 if they do your t-stat is defective.
Proper temps are ESSENTIAL for digestion.