For me it is an obstacle to privide a warm and cool spot in my tank with the dimensions being 18x18x24. It really depends if your tank is more vertical than horizontal. My pixie has no problem with his cage. Although it reaches about 86 degrees in the cage around this time of year (its 97 degrees in CA this week so we have been using the AC) the substrate is still very moist and cool.
In my other frog is in 10 gallon. i am using a reptigli 2.0 which is 25 watt and keeps the ambient temp of the cage at 82-83 degrees. It works very well and keeps the substrate wet.

I was told that frogs need uvb but i believe this was another way for the pet store convincing me buy more expensive lighting. (another reason i no longer shop there) I do plan to put my frog in a 20 gallon tank and i was also thinking of using plant lighting so that i can grow some tropical plants in there. i need some more research on plant lighting.
Grif: if you know of any links please share. Ive been changing my direction in lighting and tank setup.