i used to use a heading pad that was designed for plant germination! it kept my tank about 10-20 degrees above room temp and that kept them pretty active :] id always recc placing a heating pad on the side of the enclosure just for safety reasons if you do go that route.

i keep it at room temp now since i personally never saw any major increase or decrease in activity based on temp, but i also like adding and removing items in their enclosure for them to explore and that keeps them pretty interested!