I was wondering do crested geckos need a heating lamp or heat pad
YES! Depending upon room temperatures, cresties probably need a halogen heating lamp to keep ambient temps in the low to mid 70's F. I recommend Fluker's 8.5 inch dome for that bulb.
Heating pads will not work in this situation. Halogen lighting is much better. However, in the USA & other countries, many halogens are being phased out. You may need to depend upon reptile lighting stores for halogen bulbs.
Please don't use compact fluorescents to provide UVB. Compact fluorescents are
NOT safe.
Instead use Zoo Med's Repti Calcium with D3
lightly dusted on crickets @ 1 feeding per week dusted on all prey at that feeding + Pangea at another 1-2 feedings per week OR Pangea with Insects - 2 ounce size as a full-time diet.
Will you be feeding your crestie bugs or
Pangea with Insects? Pangea supplies an adequate amount of vitamin D3 & other nutrients to keep MBD away. Just be certain to feed it within the expiration date. That date is on the opening strip at the top. Place a "sticky" on the package when you open it
OR keep the top strip with the date.
Have a perching strip (bamboo) suspended from the screen top (with plastic-covered wires from a hardware store)
as long as the bulb isn't too warm. My crestie has a 25 watt incandescent bulb overhead in a room that's about 70*F day & night. Somewhere in the enclosure keep a longish cork bark tube or fat bamboo tube placed diagonally. Even if he has to back out, your crestie will use that as his sleeping bag.
Be sure to feed your crickets a 24/7/365 gut load diet to prep them for your gecko. I've had good results using finely ground Zoo Med's Natural ADULT Bearded Dragon Food for their food. That diet really creates a more nutritious cricket!